I went from a 5.3 to a 6.0 with a mild cam and it was night and day, thats naturally aspirated tho, on a FI buld, I think a 6.0 will deff help but it wont be as drastic, just crank up the boost on the ol 5.3, lol.

 

but with a 6.0 wouldn't you need a bigger turbo. atleast on the exhaust side.

 

I know someone with one or two laying around.
? not only will you need the 6.0 but get ready to swap out that tranny for the 80 I do not think the stage 5 will hold up with serious mojo pouring in.
How about an 8.1?

 

My 5.3L is doing very well with boost and will hang with some 6.0's no problem

 

Yes your truck 5.3L runs strong. Mark and I both race at 6000' elevation, with a Da of 8500~11000'. That will kill even a boosted truck at least half a second if not more, NA guys loose a full sec+. Running fast here all boost is a whole different ball game. That's where the torque of the 6.0L helps out.

 

Hell yeah your truck runs good! 18 psi on a stock 5.3 and 75 shot
How much timing are you running and any meth???

what is your fueling situation etc...

are you a RCSB 2 or 4wd????

sorry for all the questions this is very interesting to me

 

Do the 6.0L swap. You will love it. I have only had my truck to the track twice but there is huge difference.

5.3L - 13.4 @ 101 on 11psi
6.0L - 13.1 @ ? on 6-7psi
6.0L - 12.9 @ 104 on 8psi
6.0L - 12.69 @ 107 on 9.5psi

I think it will be in the high 11's on my 13psi setting. I lost about 3mpg across the board but I still get 18mpg on long trips.

 

im just wanting the same or alittle more power with less boost

 

Yeah, it's kinda cool running in the low 13's on the 5.5psi spring. My truck feels better on 5psi now than it did at 8-9psi with the 5.3L.

 

Because the 80E has an intermediate shaft as well as more mass in motion, it's inherently a less efficient transmission design; it's the reason why 1/2-ton late model GM trucks have 4L60's in them, because if GM used the 80E in the millions of vehicles produced since the TH350/400 there's no way in hell they would have met Congressional CAFE laws.

Mr. P.