i am looking to bore my 5.3 out to LS! specs at 99mm but i am having a hard time finding pistion at the stock ls1 bore they are all a little over sized around 99.187 mm is it safe to take a 5.3 block the extra .187 mm over 99mm ?

 

Yes you can safely bore the 5.3 to 3.905".

 

You need to have it sonic checked to see if it will go over that far. Not all Block castings are equal and a few have actually been to thin and ended up in the scrap pile.

 

FWIW Weisco now makes Forged slugs for 5.3L bores

 

Isn't the 5.3 an iron block? Curious... not positive.

 

yes unless you have an L33 aluminum 5.3 or even the Fwd 5.3L not sure what the code is for that...

 

I am doing the same thing had an iron block 5.3 bored out to ls1 specs. If you want to go with the stock size 99mm (3.898") you can get those pistons from Mahle if you go to jegs.com and look for part number 644-LS1340898F01 it comes with pistons rings pins/clips. That is where I got mine from.

 

ls4 its wat comes in ss impala its shorter due to being transversely mounted but still a 5.3 same bore and stroke and nice picture of the 55 thats my dads friends 55 bertha built by monty bernie

 

Yup thats his car, pomona 05 supper chevy meet. Also know him from PSCA. Havent been out to see his new car yet.

On the LS4 FWD application, I belive it is the crank that has a shorter snout and a balancer that hugs the block.

 

similar question... i just recently cracked a sleeve on my motor.. can get a 5.3 iron block really cheap. Looking to have it bored to diamond 3.905 piston specs. Seems the concensus is that this can be done. Correct?