reliability issues of a 427

[coggonobrien]

would I run into any issue's boring my 396 out to a 427? Obviously the cylinder walls will be thinner but will it be an issue with over heating? I need to bore my 396 anyway so I just thought I'd look into it. If questionable I will just go with the standard .030".

Thanks,
Dave

[70rs/ss]

A 427 is a 454 bore with a 396 crank, so find a 454 block and put the 396 crank into it and you'll have a 427. As for the big over bore, sonic test the block and the machine shop can tell you, but again a used 454 block can be had for pennies with fuel prices what they are.

[coggonobrien]

thing is i bought a complete 69 396 with large port ovals for 575

[MrBeast]

Well, here is where you will run into issues with a 427, for one, the way you want to do it, isnt feesabe.

If you want a 427 I would sugjest finding some one who wants a 396, then start with a mark V block with the one piece rear main, and more importanly the oiling system that is in the cam valley as opposed to the side of the block.

A 427 makes its power by being able to rev like a raped ape. So it is going to turn some RPM's. in order to do that you are going to want that oiling system along with the passage restrictors that will give you primary main oiling, and high volume pump with a large pan (8-10 quarts)

If you want a 427 that will last, that is how you do it, it wont be cheap though. If money is a concern, I would highly sugjest taking your 396, doing a good quality rebuild, upgrading your heads with an appropriately sized set, some good pistions and valve train, and make your engine into a good running dependable engine.

[coggonobrien]

cool that is exactly what I needed to hear, 427 was just a thought but i can definately live with a 402. thanks all

[MrBeast]

If you have any other motor questions let me know, I can either tell you, look it up in my library, or point you in the right direction.

[coggonobrien]

well in your opinion how would you build up a 396 with large port oval heads to run on pump gas (roughly 90 octane) hit 450-500 rwhp through a stick, and still live long as long as I don't constantly thrash it

[lytemup454]

i had a 402 in my pick up when resurching a rebuild i found out that chevy bored out most of their blocks from 67 on... so even though the badges said 396 everything was a 402. The factory squeezed in an extra 6 for us!

[coggonobrien]

pretty sure that was 69 and on

[Longhorn Man]

69 was the last year for 396 across the board. Starting in the 70 model year, they were all 402, even though many were badged as 400, and performance cars were badged 396.
GM didn't make 402s before the 70 model year.