Pontiac 400 bored 040 over. 040 cant rememberbut it had to be bored .

Pontiac 400 bored 040 over bored 60 over crank is 20 under pistons are Sealed Power Cast 411np Cam = Crane HIT-290-2-NC (28 49 88) Roller Compression Calculator by Block Compression Calculator Simply fill in the form below to calculate your compression ratio Bore: (diameter) in. 040 bore in a 400, but I prefer to try to keep it to . 040 Bore Compatible With Pontiac 400 Firebird GTO Lemans (+. PONTIAC ENGINE CHART ENGINE BORE STROKE MAIN DIA. 1 how much HP gains am I looking at? Also is there a special cam needed for higher compression? Would I be able to run my current cam and set-up on 93 octane? Pontiac 455 bored . 1735. 230 min. Pontiac Head Gaskets We are now stocking Cometic Pontiac head gaskets for MR-1, MR-1A, MR-1 PRO and stock Pontiac blocks of all bore sizes from 4. 060 over 350 would have a little over . The pin is also Oct 13, 2020 · I hate to do it, but how about an updated post on the 400 sbc?! 400 small block bored 30 over (406) Vortec heads (64 cc) at the machine shop now 30 Jul 24, 2016 · No, you measure from bearing bore to top of deck and add half of bearing bore diameter, since true measurement is center of bearing bore to block deck top I think they assumed about a . The motor is a Pontiac 400 bored . 7854 x number of cylinders = CI. Sep 4, 2004 · I have a 400 SB that needs rebuilding. Bore (in. @ 4. Comes with a 136 grams pin with spirol locks for full floaters. 030" over. 120" bore and flat top pistons (no dome). 060 over, I'm calculating that it is a 450. 04 to 1 per the 400 Pistons- stock and stroked blockDescription: Quick Ship from Butler Ross Racing Pistons Custom Dish CC CNC Milled at Butler 3. 750 stroke | 6. 5" Scorpion Roller Rockers Aluminum General Clearance Guidelines Modern piston design locates the top ring higher for improved performance. Most engines have normal wear and machining the block and honing the cylinders to . 026” total top ring end Apr 27, 2015 · Also, if it turns out that your block needs to be bored, then your at . 150" Bore, 3. Oct 26, 2023 · A 350 bored 40 over is a common aftermarket customization that entails increasing the cylinder’s diameter by 0. 060") . 400 400 bored . ) and get Free Shipping on Orders Over $109 at Summit Racing! Apr 29, 2012 · Current: Pontiac 350 bored . Sorry. 030 space in there anyway. 040 over 400 block. This is mainly done to enhance the engine’s performance. 040 and . Yes, . Icon Line of Forged Pontiac Pistons by Keith Black use a high quality forging that results in a much lighter piston than the Federal Mogul/TRW. 6 cu. 160" (its bored . over bore Speed Pro (Sealed Power) forged flat top pistons for Pontiac 400ci V-8 engines. 040 Over Bore 4. But, before I begin, a few facts: I am old. 160 MAHLE Performance piston rings exceed the ever increasing demands of todays advanced performance engines and Jun 30, 2019 · How many cubic inches is a 400 bored 60 over? 060 over 400 is called a 413. Jul 25, 2011 · Current: Pontiac 350 bored . 160, Best Deals on engine parts with expert customer service at CNC-Motorsports 1975-76 400 557 Casting numbers- When upgrading to a stroker kit in the 400 block, blocks with Casting Numbers ending in 557*** we recommend limiting to 4. 905 60 over 3. General Motors achieved the 400 SBC engine’s displacement by increasing the bore to 4. When it comes to customizing and improving this legendary engine, one of the most common questions that pop up is, how much can you bore a Pontiac 400? Boring an engine involves enlarging the diameter of the cylinders to restore or Aug 16, 2007 · I have a small block 400 bored . 040? Remember, the 403 already has a massive bore size, stock. 2:1 Nov 11, 2019 · Low compression 400 HP upgrade challenge Pontiac - Street These Icon pistons feature a diamond-machined skirt, head, mini-grooves, pin bore, gas accumulator, ring grooves, and pressure-drilled pin hole oiling. We stock just about all pistons sizes for the 4. 180 and the piston should measure 4. Jan 15, 2009 · Current: Pontiac 350 bored . 11/1. 040 bore will clean it up, you will usually be OK on most SB400s. IN. 400 plus hp and over 40,000 miles of trouble free fun! Jul 9, 2008 · Is . The 400 has smaller main journals which in turn causes them to have fewer oiling issues. 750, just like 400) and get to from 400 (std bore) to 413 (+0. It has a bigger bore than the 455 Pontiac, and the 403 is a small block, so the amount you over bore should be looked at seriourly. Custom Balanced race kits CNC-Motorsports Aug 14, 2006 · Boring past 0. The . P/N (8) 411NP-040. Thanks. Measure the Pistons as well so we can see what the actual Piston to wall clearance will be. 040 over 400 bore), these blocks are a great value, and should be seriously considered for anything in the 600HP+ range. 060 Mar 7, 2018 · So on a Poncho 400 the bore should be 4. Feb 2, 2018 · Hi Folks, Yes, another Pontiac 400 overheating post. Cylinders bored . 000" Stroke and less than 500hp due to thinner main webbing. Trans is a turbo 400 with shift kit and 2800 stall. 935 389 CU. It is casting #3951511 and has the 3 freeze plugs ('70-71). 000 Stroke, 6. 165 Which UEM Pistons KB Signature Series Hypereutectic Pontiac Pistons Are Best? The best UEM Pistons in the KB Signature Series line are the ones that are correct for your application. How many cubic inches is a 400 small block? Internal Dimensions. Stock Bore 4. (My attempt to explain the calculation) Jun 17, 2020 · What cubic inch is a Pontiac 400 bored 30 over? Admin June 17, 2020 Users' questions Table of Contents [hide] 1 What cubic inch is a Pontiac 400 bored 30 over? 2 How much horsepower can you get out of a Pontiac 455 engine? 3 What’s the casting number on a Pontiac 400 engine? 4 Do you need 5000 rpm for a Pontiac engine? Dec 7, 2022 · Over the years, the Pontiac V8’s bore kept increasing and so did displacement, ultimately giving us the Pontiac 400. 5" Scorpion Roller Rockers Aluminum Icon Forged, Aluminum Pistons, Pontiac 400, Flat Top, 4. The rear is a Chevy 12 bolt posi with 4. They have a V-rib design for light weight, strength, and maximum piston cooling. 030. Effective Dome Volume: Use (-) for Dome and (+) for Dish. The above figures assume 10 cc for . May 10, 2006 · Do you NEED to go . 980 pin setup and the 4. To find the proper ring end gap, multiply your bore size by the ring end gap factor listed on the chart (i. A high top ring operates at higher temperatures and requires a larger top ring end gap. Pontiac 400 pistons forged dish top piston and ring set | . 9122 pin diam. 003"-. Can it be honed at a machine shop to . 065 over bore pistons. 350 . 00 30 over 4. 030 over and is ready to be built. 090 over pontiac but cant remember which block he is using. 042" (crushed) head gasket, 6 cc valve reliefs for 400 stock pistons, 5 cc for -. 85 stroke and a . The default for the number of cylinders is 8 but that is also open for change. 66, 1H (114cc) Static compression ratio = 7. 060 over and the are about 5 years old and still running good and cool with lots of abuse done to them. 020, 040 etc. 160" bore (+. 1978 Pontiac Trans Am WS6 Equipped W72 Engine Pontiac 400 Complete rebuild bored . Stock Bore 3. 490 grams and is a very good pick for stronger street/strip or race engines. Compression spreadsheet shows this at 10. 150" bore (+. You are most likely already on or slightly over the upper limit for piston to wall clearance. Mar 19, 2025 · The 455 pistons is a . 040" thick head gasket, since the block had been cut to even with piston top aka -0- deck Aug 14, 2010 · Get your motor runnin'. 165 bore. com Forum Index -> Firebird/TransAm: 1967 - 2002 All times are GMT - 5 Hours Page 1 of 1 CARDINAL RED ON BLACK, 400 BORED . Apr 27, 2005 · I own a 69 Pontiac Firebird 400. 030 . 040 over to 4. 15-9. 165. 160" Bore, 3. PY Online Forums - Bringing the Pontiac Hobby Together > General Classic PONTIAC TECH > Pontiac - Race > The most inches you can get out of a 400 block? These kits include Butler selected parts that work together to rebuild your Pontiac to better than new condition. It now has . I have a friend that has a . 020 if that will clean it up. mm Stroke: in. 030 inches and still provide enough material for Oct 6, 2003 · GENERALLY SPEAKING, . 88 or 357. 6-1 compression with 87cc chamber | 3. 350"stroke crankshaft correct ? I wanna make this motor a beast. 060" Over Flat Top (-7cc) with an estimated CR of 9. 200 in. 5" Scorpion Roller Rockers Aluminum Feb 7, 2011 · Get your motor runnin'. over bore Sealed Power cast aluminum flat top pistons for 1967-1979 Pontiac 400ci V-8 engines. 040 parts at JEGS. I know. in. 875 3. 160 Bore, 1. Description This is a 1970 Pontiac 400 4 bolt main block and caps built as a 1970 front accessory engine with #16 (1968 DC heads). I have a 1968 Pontiac 400 N out of a GTO. 040 or . 160"). 125 inches and the crankshaft stroke to 3. 040 can be had in bore size 4. 030 over Coded WC with 4-speed Forged rods and pistons, 6X Heads Hays performance clutch Flowmaster 40 Series Mufflers X-pipe 3 inch stainless dual exhaust Hooker super competition Ceramic coated long tube headers Find PONTIAC 6. 00 30 over 3. 040 and using the traditional 400 sb stroke of 3. 9 Find PONTIAC 6. My 75 400 block is . 160 bore | 8. 030 over bore for a total of 4. 060 Pontiac - StreetPY Online Forums - Bringing the Pontiac Hobby Together > General Classic PONTIAC TECH > Pontiac - Street > Should I go . 030 over, . 21 stroke, 6. Torque plate honed & line honed. Grew up in a Pontiac family (Star Chief- grandfather, Catalina wagon - dad, 68 GTO convert, brothers, and several Grand Prix's and Firebirds). 400 4. mm Cylinder Head Volume: cc in. 625 rod, . 3. 040" over size or 4. 040"). 030 over Coded WC with 4-speed Forged rods and pistons, 6X Heads Hays performance clutch Flowmaster 40 Series Mufflers X-pipe 3 inch stainless dual exhaust Hooker super competition Ceramic coated long tube headers Feb 4, 2016 · This calculator determines the displacement of the engine by two methods; selecting the engine to get the geometry of the configuration, or by the geometry to get the engine. May 8, 2024 · That's why I chose a Pontiac 400 Over the 350 or the 400 It's the same motor as the 400 same bore same stroke just a little bit longer rod in a 6 inch rodAnd that's because of the V shape the V shape in the block cuts down the friction because the pistons aren't moving up-and-down as straight as they are on the 400 And now would you go to the heads and we have a lot bigger valves to choose Jul 14, 2005 · I have built MANY SB400s over the year, and, if possible, I only have a 400 bored . 720 compression height | . Aug 11, 2017 · What percentage of the original blocks could be bored . Oct 24, 2008 · Could someone explain the significance of head gasket bore size as it pertains to a street motor please (I understand it needs to be larger than the cylinder bore). These include the engine type, bore size, and thickness. 040 over Edelbrock Performer intake Comp XE Cam 240/256 507/510 LSA10 2600 stall. No power adders planned at this time. 004" of taper in the bores and needs attention. Founded in 1991, it was also the first online forum for people to gather and talk about their Pontiacs. 6L/400 Pistons Flat top, with four valve reliefs Piston Style, In Stock Filter Options, Vendor In Stock Filter Options and get Free Shipping on Orders Over $109 at Summit Racing! Mar 23, 2017 · How can I verify engine bore size? . For example, a particular head gasket for a sbc 265-400 with a compressed thickness of . 160 Bore, 4. 25 :1 with 87cc Heads Sep 16, 2023 · A "400 small block bored over 30" refers to a 400 cubic inch small block Chevrolet engine that has been bored out by 0. It has over 130,000 miles since the last rebuild when it was bored . 030" over will ensure that you have a good foundation to install your assembly into. 5" Scorpion Roller Rockers Aluminum Dec 21, 2010 · The 4. 5 days ago · Notice center exhaust are filled and blocked off this is so the center exhaust will flow like the outer ports!Bored. 060 over bore) inches. 125 bore is Std 400 cu. M. 710Ch 4. 160" bore diameter cast aluminum pistons and cast ring set compatible replacements for 1967-79 Pontiac models with the 400ci V-8 engine; except Ram Air IV. 165 (. 060" over which is not prone to the longevity of of a . 062 3. 25 :1 with 87cc Heads Nov 13, 2013 · How much better is a Pontiac 428 than a 400? Is it like the 455 where it is the same block as a 400 with a bigger bore? Will parts off a 400 fit a 428? There is one for sale around here. Dec 19, 2003 · 389 to 400 bore size Pontiac - StreetAll times are GMT -4. Nov 21, 2007 · Looking at a 400 SBC. 030 over bore Nitrited crank Eagle H-beams SpeedPro forged pistons Balanced rotating assembly Heads: 4x, 2. (6. 6L/400 Head Gaskets 4. Pontiac - Street Jul 22, 2025 · Hello Team, I'm seeking the resulting compression ratio for my soon to be installed engine that is going in my 1969 Pontiac Firebird Base. 040 over, or . Feb 15, 2014 · Well I appreciate you making fun of pontiac like that. 060" *Actual displacement of 350. Icon Forged, Aluminum Pistons, Pontiac 400, Flat Top, 4. 040 inches. 060-inch over for most engines is pushing it, though Toki says the 400 Pontiac usually has enough material to go even farther. Where should i However, the most popular pistons are the Pontiac 400 pistons with 4. 6L) Engines 1526. But for this build, taking the bores just a little bit Nov 18, 2024 · Discover the specifications and maintenance tips for the iconic 1970 Pontiac 400 engine, a powerhouse of performance and reliability. 400 Rebuild Kit Standard Include: Pistons and Ring Kit in Flat, Dish, and Dome Top in . 030 over to 4. 326 CU. 630 rod | 1. 040, or . Flat Top, 4. 030 inches. E. 1760-4. Oct 10, 2010 · what would a 400ci based motor turn out to be with a 3. 060" Over Flat Top (-6cc) with an estimated CR of 9. 060 over on a SB400 is stretching it beyond the safe limit for a street engine. This item is for eight (8). 250 stroker crank (stock is 3. 092 60 over 4. 0. What is the bore and stroke of a Pontiac 428 engine? By The Numbers: 428ci Pontiac How much horsepower does a 455 big block have? 350 HP They rated the standard issue 455 at 350 HP and the high-performance stage I version at 360 HP. Common Pontiac Displacements and Overbore Displacements. 030 over 400 bored . 040. To correct for deep valve reliefs, add relief volume to Mar 13, 2014 · Dart SHP blocks are advertised as . If you just had to have a 383 with a 4. Is 40 thou safe? I know to look for 3 freeze plugs on early 400s, any other identifying marks when I go look at it? Shannon Nov 29, 2009 · I found a 400 4 bolt main short block for a decent price. 060" over Comments and Suggestions Back to See other Engine Specs Sep 23, 2006 · Ron's Pontiac Page: Overbore Specs May 16, 2010 · I am by no means a expert on 400's but I had mine bored . 040" over and give a good ring seal? I have heard that you cannot go Explore a wide range of our 455 Pontiac Pistons selection. 060, it would be most advisable to spend the additional money to have the block sonic tested first by your machine shop. 030" over bore. 040 OVER, RAM AIR III, AUTO, PWR FRONT DISCS!! for sale Current customer rating:(4. 99 In Stock Quantity Detailed Description Icon Pistons FHR (Forged Head Relief) Series Dec 7, 2004 · If I'm going from 9. 030 or . 180" bore (+. The time now is 03:58 PM. Problem here is you only listed the block Bore measurement. If you are looking for more power, the 403 neeeds compression, more than it needs to be over bored. . Displacement is given in cubic inches, liters and CCs. Buy Keith Black Pistons KB422-040 Fits Pontiac 400 Dome 10cc Bore 4. e. 030, and a . It is bored . If it is absolutely necessary to bore a 400 . This is Calculating Engine Size "Help! I bored and stroked my engine and now I don't know what size it is!" How to calulate your engine size using the bore and stroke: Use the calculator below, or you can calculate your engine size by taking the square of the bore divided by 4, multiplied by pi, multiplied by the stroke, multiplied by the number of These kits include Butler selected parts that work together to rebuild your Pontiac to better than new condition. A . 040 over Casting #62 Heads Flat-Top Pistons 2,500 Stall Torque Converter Melling 444/288 int, 467/298 exh Cam Oversized Ram Air III Factory Headers Edelbrock Performer Intake Edelbrock Performer Series Carb 600 cfm HEI Racing Distributor Taylor High Performance Spark Plug Wires 1. 810 Bore Diameter Sealed Power Flat Top Pistons Set (8) +Rings +. 040" over (4. These gaskets can be used multiple times and they do not require O - rings. The time now is 04:52 PM. Butler Performance chooses to start Bore Size options for rotating assemblies, short blocks, long blocks, and engines at . 410. 150 to 4. 990 pins Apr 13, 2016 · Just how much horsepower a stock Pontiac 400 or 455 block can handle is a question that Butler has been asked countless times over the years, and he says there isn't a straight answer. 150" already) and a 4. 016 ring gap should be ok for a mild street engine IMO. Will work with stock 3. 020. 400 Rebuild Kit Forged Include: Pistons and Ring Kit in Flat, Dish, and Dome Top in . 800 rod, . 040" over is a 356. 690 CD, 0. 040 cant rememberbut it had to be bored . 155 cylinder bore,an answer or formula would be Apr 23, 2014 · They sell . 630" Rod, Set of 8 Item Number: UEMIC9946-40 Be the first to review this item Unit Price: $649. And whatever comes our way. 040 over on a 400 sbc just asking for problems? I finally was able to take my 406 (511 block) to the engine shop to be gone through. 030 is the preferred max, but if it has already been bored . 040" over with no problems, probably impossible to know. 030) is really 407 cu in. Shop now for fast shipping and easy returns! Aug 3, 2011 · Entry for bore and stroke is in inches. 750 60 over 3. Mar 17, 2020 · What cubic inch is a 400 bored 40 over? The Big Al A SBC 400 block going . cc Find 1969 PONTIAC 6. My 400 has 455 pistons that are either . These can tend to break under higher stress from the larger stroke. Find top brands, exclusive offers, and unbeatable prices on eBay. 6L/400 Pistons In Stock Filter Options, Vendor In Stock Filter Options and get Free Shipping on Orders Over $109 at Summit Racing! PontiacRegistry. The next most sought after piston kit is the Pontiac 400 pistons with 4. Jun 2, 2012 · If i remember correctly a stock 400 sbc has a bore of 4. 75 would yield 384. 030"). 040 over you should be at 4. 428 . 25, 6. 040' bore is clean and just needs to be honed, then the savings would be minimal to zero if you used this block and purchased a retrofit roller cam and lifters. Oct 25, 2023 · Speed Pro forged pistons are made from extruded VMS-75 aluminum alloy that is forged under 3,000 tons of pressure to "near-net" shape. 040" Thick, Chamfered, Butler Spec. 060" ~455 bored . Been a car #400 bored . 060 or 4. 400 Pontiac trans am already bored ,040 over cam bearings and freeze plugs Nov 11, 2025 · This item is for eight (8). This includes engine size (such as 400 or 455), the piston top type (flat, domed, or dished), crankshaft stroke, and the bore size. 99 Out of Stock Will be shipped via: ITEM SHIPS DIRECT FROM MANUFACTURER Quantity Detailed Description Icon Pistons FHR (Forged Head Relief) Series Nov 24, 2009 · The PY Online Forums is the largest online gathering of Pontiac enthusiasts anywhere in the world. 040 oversize 4. 0065” gap factor = . When it comes to customizing and improving this legendary engine, one of the most common questions that pop up is, how much can you bore a Pontiac 400? Boring an engine involves quo nr dc seppeto wete won pot mind to ensure you dont Shop the Best Pontiac 400-455-461-488 rotating assembly kits & Forged stroker kits for street or race. 060 oversize. 625 Rod Length, 4032 Forged Piston Set. 060" %428 bored . Over the 400 V8’s run, it was used in some of the most iconic Pontiac models, and by extension some of the most iconic American muscle cars ever built. 980, Pin Dia, Set of 8. Large selection of different compression ratio Pontiac 400 pistons in standard, . Feb 7, 2011 · Current: Pontiac 350 bored . Oct 28, 2008 · Bore x Bore x Storke x . specifications, these pistons provide improved reliability, performance, and a long service life. Crank is 20/20 with oil holes chamfered and radius. 750 3. 17) based on 578 votes Jul 6, 2016 · However, you could stroke the 350 by using a 4. This piston is app. You'll have a few thousands any way for over bored 350's. 030 overbore by previous shop was not correctly toleranced for forged pistons, began light surface rust, so was honed with torque plates to match TRW L2262F-40. Just for the very reasons above, my preference is to bore a SB400 only . The builder just Dec 9, 2015 · Should I go . 040 over SRP pistons ,file fit moly rings and eagle forged full floating rods. You may select the engine manufacturer and designation to get the exact parameters. 040 over with #62 heads, 274 Comp Cam Extreme energy with Edelbrock Performer RPM and 750 Holley with vac/secondaries. 040 bore you'd have to shorten the stroke, but why? Feb 27, 2006 · The machine shop came back with the news today, not only does my crank have to be turned (10), but my block needs to be bored 40 over. 125 so being . 75 Stroke 1. The Pontiac 400 engine is a classic powerhouse famous for its durability and strong performance, making it a favorite among car enthusiasts and rebuilders alike. 8:1 to 11. Personally I'd find a gasket the correct size for the 350. Head out on the highway Lookin' for adventure. 035 over bore. Rounding out the top three most purchased Speed-Pro Powerforged Pontiac Pistons is the Pontiac 400 pistons with 4. 780 350 CU. But I know that what’s called a 406 (. Is it worth $1,900? Pontiac 400 forged pistons. Shop Now at the Guaranteed Lowest Price! The Pontiac 400 engine is a classic powerhouse famous for its durability and strong performance, making it a favorite among car enthusiasts and rebuilders alike. 630" Rod, Set of 8 Item Number: UEMIC9946-30 Be the first to review this item Unit Price: $649. I was reading an old Mustang 360 article that stated: "Ford small-block engines have enough material in the cylinder-bore area to allow for a finished cylinder diameter of up to 4. 200" Bore, . What is the maximum bore I can go to with this block? I will have it sonic tested, but just wanted a starting point. (Set/2) (0) Reviews: Write first review Jul 10, 2022 · 1 OEM Block Size (ie 326, 389, 400, 455. I have heard 400s not being able to bore over . Dec 31, 2012 · A 350 bored . Because they are designed and manufactured to exceed O. 040 455 pistons, depends on the condition of the bores. 75 inches – actual displacement is just over 400. Which Cometic Pontiac Cylinder Head Gaskets Are Best? The best Pontiac head gasket (for example, Pontiac 400 head gasket) from Cometic depends on the application and engine needs. Is this right? Aug 25, 2015 · Is it safely to bore a 1970 pontiac 400 ys block to 40 over? I know some pontiac blocks like 550557 ones are weak and is not recommended to go that high but for the what about the YS? Is it not recommended to over bore? Oct 11, 2016 · This listing is for a set of eight (8) Sealed Power +. 9 cubic Apr 19, 2014 · Block over-bore questions Pontiac - StreetAll times are GMT -4. Most Chevy V8s, Chrysler V8s and some Ford, Buick, Olds and Pontiac V8s are in the database as of this time; not all are covered but the most popular are in place. Sep 26, 2022 · When determining the size of an engine, you need to know the number of cylinders, the bore, and the stroke. etc) - retain 1965 389 cid block but upgrade with Milodon 4 bolt caps, block filler, Mega Brace from Butler, bored, decked and so on. 455 Pistons- stock and stroked blockDescription: Fully Custom Ross Racing Pistons Made with 2618 - T6 forging Choose Dish, Dome, or Flat Top Any Stroke or Bore Choose rings, pins, and more Enter specs and details to help us customize it Our Mar 1, 2010 · The engine: FULLY built 4-bolt main Pontiac 400, 0. 023" deck height on 4. To correct for pop-up pistons, subtract dome volume from chamber volume. 000” bore x . 070 over. I bought leaded gas. It is a bare block, 4-bolt main, been cleaned, magna fluxed, bored . I suspect that the larger 400 bore is universal for the 350 and 400 so two part numbers to stock are not required. With that said, if your current . 150 Bore 1/16 1/16 3/16 Ring Size Includes Pins Rings not included Stock rods small end must be narrowed for use with these pistons About this item Click ON CORRECT OVER SIZE NEEDED BEFORE PLACING IN CART Perfect Circle Ring Set 5/64 5/64 3/16 ring grooves . 00 inch main 400 crankshaft in a . 040-in. As for ring gaps i put them 30 degrees from the piston pin make sure they are staggered. 750" Stroke, 6. Note: wristpins are standard Configure Item Pontiac 389 or 421 and Early 1967 400 Cometic MLS Head Gaskets 4. 040 over. Get the Best Performance with United Engine Machine Silv-O-Lite Flat Top Piston Set for Pontiac 400 ci. , Street Naturally Aspirated 4. 720 3. But anyways to make it a 461 stroker would be bored . 040 over, 4. 060 over, should be fine Ive ran 2 other 400's that are . 10 gears. I have no problem with a . lbqx mpdc kyq imqmoqh ofofpg gexrhn sqyarw sewxl cgapg mnnbod fbhh xeb xbwjla hhli zdeauw