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Old 04-26-2022, 07:39 PM
hurryinhoosier62 hurryinhoosier62 is offline
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Join Date: May 2006
Location: Floyd Co., IN/SE KY
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Quote:
Originally Posted by blackadder View Post
If I use 455 pistons will that not just be a 455? I have all the parts to build a 70 455 HO that are new less the block. A fella south of me has a 70 455 .030 over coded Hi HP block which will match the pistons I have but its rather $$. Cannot a 455 crank run 421/428 rods and pistons ? Or is the stroke an issue although I believe the deck height of all Pontiac engines is the same, but could be wrong. I am under the impression that adding just the crank from a 455 to either engine will yeild a 440 CID motor approx. Thanks for all the replies so far.
ALL 3.25” main Pontiacs run the same rods. The difference is in the compression heights of the pistons. To use a 455 crank you must use the appropriate 455 pistons or a custom piston with the correct compression height useless you are using standard bore 455 pistons (4.1510).

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