They have the same size pistons as the 5.3L. The 4.8L has a shorter stroke. The 4.8L's do tend to hold up better because of this and people spin them higher. If you go FI no need to spin it insanely high though.

 

Any LS is capable of stupid power. The question os which one will be most drivable at those power levels and likely last the longest. The more cubic inches an engine has, the less boost you need to run to reach the power level you want. The less boost you run, the more drivable your ride will be when not in boost. Lower boost on a bigger engine tends to be easier on the hardware than high boost on a smaller engine as well, which promotes longevity.

 

^Good point above for the OP. I'd prob just look for a 5.3L and boost it. The pricing will be about the same on the 4.8L vs 5.3L. The pricing of a 6.0L is going to be quite a bit more compared to the 5.3L unless you are a lucky sob and find one for a steal. The pricing is what normally deters people from getting the 6.0.

 

There's someone on here that's looking to break 700 RWHP on a Turbo 6.0 with a stock bottom end.

The 4.8 is just a de-stroked 5.3, same block, same pistons, same bore size.

 

slightly left field here, but mathematically, if you put a 4.8 crank in a 6.0, you'd also get a 5.3 - just a higher-revving, biger-bore version. has anybody tried this?

 

De-stroked

a 6.0 with a over bore say .030 or .040 (not sure on the biggest you can bore over), and the smaller crank like the 4.8 in it! boy oh boy... You will need the bigger pistons for the new bore, and maybe custom-ed so the piston skirts are right to match the smaller crank.

some sort of destroked combo, i Bet that thing spins 10K RPM and make some serious mid to top end power

maybe a expert chimes in.

 

I believe the stock bottom end on the 4.8/5.3l is supposed to handle up to 1200hp while the bottom end on the 6.0l can handle 900hp. But if you plan on making 700hp im sure either of these motors can reach your goals.

 

I think I have decided that I will go with the 5.3L, I was looking to get better gas mileage but I don't think the gas mileage from the 4.8L to the 5.3L is so bad... What turbo should I use, I was thinking something between a 72mm-78mm?

 

Im from tenn,an i bought 06 GMC RST with 5.3 xtended cab.i had it dynoed its got 400ft lbs tq now an 330 rwhp.i work in const an put 30,000 to 40,000 miles a year on it .I wont 500 to 550 hp at the rw . but i can get more rpms n more hp from the 5.3 than the 6.0 .the 6.0 weights more n take more power right ?