Well starting my turbo build pretty soon, front mount from alen or kb,z06 cam,342's, circled 2c,arp studs,meth and about 16-20lbs. I was going to put my stock 5.3 heads on but would it be worth putting stock 241's,243's,317's?? I won't be doing any work to them just leave them stock, what you guys think, wil it be worth it?

 

if your just going to use stock heads im pretty sure all 3 of those you mentioned will give you lower compression (better for boost) but the 862s flow pretty good too. just get em P&P

 

there is a member here selling a set of PRC 2.5 5.3 (862) heads pretty cheap. Ported and polished and oversized valves.

 

really not much of a need to P&P from what ive seen.

 

Some good info. https://www.performancetrucks.net/fo...d.php?t=447449

Rick

 

Do the 243s

 

thats what i was told.... i guess 317's would drop tooo much compression

 

Yea I've heard of some other reasons not to use the 317s on 4.8s and 5.3s too

 

what kind of reasons?

 

I'd go with the PRC 5.3L heads stage 2.5. Less compression makes for less power and if you aren't planning to run more than 15psi there would be no reason to drop from the stock compression which is already low. Lowering the compression would make for less power when not in boost for sure, slower spool time, and less overall power even when in boost. This isn't the 80's where you automatically just lower compression when adding boost. People build newer boosted motors at around 9:1-9.5:1 regularly which is where a 5.3L is stock with the exception of the L33 and NNBS engines. The PRC heads will keep compression about the same and flow quite a bit more air which will help make for more power with less boost.