How far can you overbore these blocks? I have a line on a really cheap 5.3 but it's going to be going in my 69' Tempest. If I did it I would want to build the engine with a single turbo but no one has pistons for the 5.3 I've read a few posts that say bore it out but that's a HUGE bore increase (3.779 to 3.893) I usually don't like going over .060 on my small blocks I've built for my previous cars and the one I did for my friend's IHRA car up here. If I can bore it safely to the 5.7's bore then we got a deal, just trying to clarify before I go get the thing. Thanks

 

Oh and if not I'll be scowering around for a 6.0 for a little bit. I want an Iron block.

 

A couple of guys have bored it out to stock Ls1 bore size (3.905 I think) and made iron block 5.7s. AS long as the block checks out okay, you'll be good to go.

 

Alright sounds good, thank for the info. Just seemed like a BIG overbore lol