lavoy

iTrader: (2)

ok i recently broke my ls6 in my 71 datsun and am looking for the best bang for the buck to get back going, it seems these 5.3 motors will fit the bill. so i would like to know whats the hot ticket with these things to make around 700-800 whp. my ls6 was making a tad over 600 at 11 psi before i turned it up to 14 and broke 4 pistons. i have the ls6 so if i need to use anything from in on the 5.3 i can swap it over, i am pretty sure i should use the cam and get some pac 1218 springs, what about my ls6 heads would they be better or worse then the stock 5.3 for meeting my goals? what else should i consider doing to meet my goals? im thinking of doing head bolts but not sure about much else. so any information or advice would be great.

Snkebait95

iTrader: (16)

This should give you an idea

https://ls1tech.com/forums/dynamomet...urbo-6psi.html

Ls6 heads will drop to compression to around 8.7 its not really needed but with less compression you can run more boost. Car craft, gmhtp, and hot rod mags have all done dyno tests with 5.3s and boost do some research

lavoy

iTrader: (2)

been doing research but my internet is worse then dial up so its easier to compile in one thread.

also what are some normal timing values and different boost levels i should start out at.
and my car is set up as speed density should i convert it back to maf? or just stay sd

Snkebait95

iTrader: (16)

I think you could run 14 psi on a 5.3l and not break anything, but im far from an expert. I would carry everything over from the ls6. Im doing a boosted 5.3l in my 95 z28 with ls1 accesories and a 85mm bbk ssi intake and tb.

Snkebait95

iTrader: (16)

The guy in the link made 5xx rwhp and 45x ftlbs tq on 6 psi with a stock 5.3l cam and heads, ls1 accesories and a fast 92.

Oh and ls6 cams seem to be great boost friendly cams in the 5.3l. When im done, im building a spare 5.3l for the hell of it. Theyre so cheap right now and make such great power with boost im afraid they will get more expensive in the future. If one breaks, just crap out another $500 and youre ready to run again lol.

lavoy

iTrader: (2)

thanks for the info , i think from what i read i will stay with stock heads maybe add some arp bolts and zo6 cam and ls1 intake and have at it

lavoy

iTrader: (2)

got ripped off and was sold a 4.8 not a 5.3 so im waiting to see if they will exchange it or if im stuck with the 4.8

chrisfrost

iTrader: (8)

I would say 700-800 whp would be pushin it a little on stock bottom end if You plan on puttin that down on any kind of consistent basis . On You tube there's a vid of a silverado 5.3L on dyno adding 24lbs. hittin 2000hp so can it take it ,,,,yes but how many times ? ,,,,,,,,not forever that's 4 sure . For a while ,,,,,probably ,,,,,,to be safe 4 the long haul 600 to the wheels is the max I would go or just don't nail it all that often .