block help
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Joined: Feb 2003
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From: anderson sc
block help
i've got another project that i need a little info on. i have a 400 big block engine. all in good shape and already rebuilt. thing is i would love to have a 427. from what i read, all i need to do is bore it out. the stroke is the same. the block is from a 72 el camino i think. what i'm asking is that can i bore this block out safely to a 427 and still have a strong enough block? i know a 427 is probably a different block, but is it possible? thanks for the advise and tips fellas. might be my new vette hauler.
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From: anderson sc
it's kinda a sketchy deal. i belive they called em 396, 402, and 400. all were big blocks and all were the same engine, i think. but yea it's a chevy motor. so anyone got any clue on this? be nice to have a 427 with some aluminum heads that flow nice, forged bottoms, and nice fuel injection that makes some stupid power.
Melting Slicks
Joined: Jul 2004
Posts: 2,018
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From: OR
The smallest cid big block I recall was a 366 which is a truck engine. The biggest that I recall is a 454. If you have a big block it's probably a 402. I think the 400 is a small block. I think there are more differences than simply the bore and stroke. Like the heads are different, even though they look the same looking at it setting in the engine compartment. I can't answer your question, a machine shop probably could. However, if it were me and I wanted a 427, I'd start with a 427. If you really want a strong good running driveable big block, look for a 450 hp 454. That's about as strong as the factory hot rod engines were in those days as far as I can remember.
Team Owner
Joined: Sep 2001
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
If its a BBC, you can have it thoroughly checked out, and then do the 427. But it needs to be checked out in every way possible by a shop.
Its a pain to fit in the engine bay but it will, and youre going to have to deal with the reverse cooling switch to normal.
Its a pain to fit in the engine bay but it will, and youre going to have to deal with the reverse cooling switch to normal.
Le Mans Master
Joined: Dec 2002
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From: Santa Teresa New Mexico
Originally Posted by newbecorvetteguy
The smallest cid big block I recall was a 366 which is a truck engine. The biggest that I recall is a 454. If you have a big block it's probably a 402. I think the 400 is a small block. I think there are more differences than simply the bore and stroke. Like the heads are different, even though they look the same looking at it setting in the engine compartment. I can't answer your question, a machine shop probably could. However, if it were me and I wanted a 427, I'd start with a 427. If you really want a strong good running driveable big block, look for a 450 hp 454. That's about as strong as the factory hot rod engines were in those days as far as I can remember.
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Joined: Feb 2003
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From: anderson sc
well the thing is that i already have this engine, which is a big start towards what i want. and yes it is the 402 big block. what i meant earlier is that the 396, 400, and 402 BB's are all the same engine, just differnt notation. i know they are differnt from 427, 454, and other BB's. anyhow, i'd like to put it in my car, but that isnt the plan. i'm working on a truck restoration that could be a vette hauler for when my car breaks down, which happens alot lately. but i'm glad to hear i can bore it out to 427. i'll just have to have it checked because i dont want stuff flyin apart on me. gonna be nice ,, thanks for the info guys. any more advice or tips are welcome.
Race Director
Joined: Jun 1999
Posts: 14,924
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From: Merritt Ils Fl
The 402 came with two block casting numbers,3969854 and 3969290. Same blocks were used to build 396s, but you knew that. The 402 was 4.125X3.76 while the 427 was 4.250X3.76. That means you have to bore that puppy .125 over. I am not a big block person but that seems to be a bunch of boring.
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