I blew up my ls1 motor and have a few questions about the 5.3.... since there arent many people on ls1tech running them i figured i would ask here.

My plans are to build a budget boost 5.3l motor for my 98 TA. I want to keep it budget and make 550-600hp here is my parts list so far:

1999 5.3 junkyard pullout
ls6 cam
317 heads (not sure wether to run stock 5.3, 241, or 317 heads)
Meth/water injection

I already have PRC dual springs, FMIC, 42lb SVO injectors, Garrtet GT70 Turbo, ect....

QUESTIONS:

1) What year 5.3L would be best for my goals?
2) Can i make 550-600hp on stock 5.3 or my 241's or are 317 a must?
3) I never read about anyone changing pushrods.... are stock good to 550-600hp?

I am open to any and all advice from any of you that have done this!!!

Thanks!

Blaine

 

to answer one of your questions...i would get hardend pushrods for sure

 

I figured.... but i never read about anyone upgrading them.. since im using dual valve springs im gonna want some hardened pushrods.

Thought i would ask though,

Thanks!

 

no prob man...most cam swaps ive seen run the hardend pushrods for cheap insurance

 

your ok with the stock heads for 500+hp (~9.5CR) but with the 317's you'll drop compression significantly to allow way more boost. You don't say if this is a DD or for fun car.

 

Nothing wrong with what you have but FWIW in 03 GM went to a piston with coated skirts to help aleavate piston slap.

317 are really gonna drop your compression but I am not sure how much

stock 706,862 is like 61cc with 200cfm flow with 9.5:1 compression

stock 241,243 66cc-67cc with 210 cfm flow

stock 317 71cc-72cc with 210 cfm flow


I would also recomend upgradeing rod bolts and going through the rest of the motor to make sure its up to the task if there is a lot of wear you may be right back to square one....

good luck with your build!!!

 

SWEET! Thanks for posting this thread...this is exactly what I will be doing on my 95 Z28. I was wondering about heads/compression ratios as well. I'll probably have whatever heads I go with ported & go with some sort of cam for boost.

 

The best years were the 05' or so and newer as they had the better rods. Pretty much all the year's for 5.3L's will do the job. Stay with the stock heads. Your 241's aren't going to be worth swapping for. The stock compression is already low on a 5.3L and making that lower will just kill spool time with a turbo. As for the pushrod thing, I'd recomend changing them. With a stock cam it wouldn't normally be needed. With a turbo you'll want to run a good valve spring if you plan to run higher boost levels. Any spring stiffer than the LS6 spring should really have a stronger pushrod than stock. You'll want more cam anyway as any help to get you over 500RWHP is nice to have.

 

Holy crap! Thanks for all the info guys! So if i didn't bother with the cam right away and just boosted the stock 5.3l with ls6 intake and ported TB what kind of numbers could i expect?

The car is a weekend warrior.... and it goes through hell with just about every mile to be honest, lol.

 

I have a 08 5.3 SCSB and i am making 484 to the wheels... i cant decide to go with new cylinder heads and a custom cam or just swap it for the 6.2 L92 when i get the dough!? I know the L92 comes with great heads but its $6400 opposed to about $4000 for the install of the heads and cam package and re-tune on the 5.3