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396 +.125

76zimmer

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I heard of it being done to get a 427, but has anyone had 1st hand experience with this? I have a line on a 396, 325hp from a Camaro, and was just thinking?
 
Back in the day, we used to do that, but ONLY with 65 blocks. They were supposed to be the same core as a 427, so lots of meat in the cylinders.
 
Only way to tell is a sonic check. It may be possible with a sleeve, but the cost would be prohibitive for the latter...
 
Why overbore (especially that much) if you don't really need it? Other than to say, "Mine is bigger than yours."?
 
Heck, 396+ just whatever it takes to clean up the bores=more life down the road.

If you want more cubes, go get a 454+ and leave the smaller stuff to the nostalgia crowd. :)
 
396 and 402 same basic block.

427 and 454 same basic block.

396 and 402 and 427 same cranks stroke .

454 bigger stroke.
 
This all basically came out of a beer/bench racing session.....I'm sure you know how those can get. Anyhow some say yes, some say no. Just wondered if anyone has done it for themselves, and the results after hitting it hard.
 
Like I said earlier, I did this back in the 70s. ONLY the 1965 396 blocks were capable of boring 1/8". Even the lopo 325 horse motor used the same block as the 375 horse version. We used to scour junkyards and grab every 65 block we could find, for this reason. Course, this was back when a JY motor complete was 25-50 bucks.:eek1: :eek1:
 
A 396 has a 4.094" bore so you would have to bore it .156" oversize to get a 427 and it isn't possible to overbore that block that far.

396 = 4.094" bore / 3.76" stroke
402 = 4.124" bore / 3.76" stroke
427 = 4.250" bore / 3.76" stroke
454 = 4.250" bore / 4.00" stroke
 

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