396cid+ LT1/4's?
 

Hi guys, I was just gonna build a 383 LT1 for my 96 Z28, but I was searching around and saw 396,400, and even a 409cid LT1 on the web... Just curious does any have a or know about a 396 or larger LT1/4 motor? I know the stroke for a 383 is 3.75 and for the 396 is 3.875 also what difference does the overbore have? (the 409 i saw had a 396 crank with 1.000 overbore...)
Thanks for your help...

A 396 LTX engine will have a 4.03 inch bore and a 3.875 inch stroke.

The real question is if you wanna go that big how much $$$ you got?

You can put a 4.00" stroke in a LT1 block, but it's a tight fit and you have to do it the right way.

Larger bores have the problem that you need to sonic check a bunch of blocks to see how much you can bore them out, so get a few blocks if you want to go much over .030 and have it live for any amount of time.

BTW the 409 didn't have a 1.0" overbore, it was a .100" overbore and that was one freak LT1 block if it lived.

Bret

thanks for the correction your right it was a .100 overbore...

Better stick to 383/396. Even the price difference from 383 to 396 was a little more than I expected. I probably should have saved the money and went 383.

A few guys on the Impala boards have done the 409s but for nostalgic reasons, they don't even recommend it from the performance standpoint. IMO stick to a 383/396 and if you have the money to burn that it would take to go bigger sink it into the topend you will be better off. Another alternative would be convert an aftermarket gen1 block to accept the LT1 specific stuff but that is really going far.

Running a 401 CI LT-1, 4.060 bore. 3.875 Crank.