Mileage stayed the same (17-19 mpg) with 4x4. Swapped in a 6.2 later with a 6L80E/AWD and it still stayed the same. Hard to drive a 400+hp RCSB like a sane person though

 

Good Info!!!

I have heard that but have never seen one my self.

I just wanted to make sure people knew that it was NEVER mated to the 4L60E

 

The wide flange 4.8L crankshaft was casting number 12553312, while the narrow flange crank had a casting number of 12553482. The wide flange 6.0L had a casting number of 12552215, whereas all the other Gen III engines had a narrow flange crank with a casting number of 12552216. Even with all the different displacement engines having the same casting number crankshaft, this doesn’t mean the crank can just be pulled from one engine and installed in another, as they were individually balanced and the car engines even had gun drilled crank, so re-balancing would be prudent.

 

getting more and more excited about this swap. Only sucky thing is that i could get a 5.3 for half the price of a 6.0 though..

 

Sounds like what you need is a 5.3 with a turbo

 

Why even go through the trouble of a 5.3 swap? The 4.8T seems to be a proven setup..When I buy my GMT900 rcsb I will turbo it and avoid ALL the other headaches..

 

not swapping till the 4.8 is worn out, just planning ahead and figured since its a direct swap, might as well go a little bigger, no turbos or anything..

 

Just said it to be funny. 4.8T does seem to be a proven setup. I probably wouldn't do the swap either if I was going with a turbo.

 

The 6.0's make a bunch more torque stock for stock.

 

5.3's around me are gettin cheaper and cheaper. i've found 10 within an hr drive of me for $450 or less, complete engines. 6.0's are $1200 or more. If it were me and i had a 4.8 i would keep it, buy a spare 5.3, maybe 2, and then full bolt on's and some sort of FI or sweet nitrous setup. I think i would only get a 6.0 if i could find one on the cheap.