Ok Im going out of my mind with this thing. My trans was slipping and the stock 5.3 wouldnt rev past 2500 and bogged and bucked, so I said screw it and bought a 6.0 and 4l80e... And still the same problem with not being able to rev... so heres the specs.

00 RCSB 4X4

00 lq4

799 heads
TR valvesprings
TR 224 cam
TR pushrods

02 4l80e stock(4x4)

Ls1 fans-nelson harness
CAI
Pacesetter LT
Dual 3 inch ex out in front of pass tire
Dual 3 in high flow cats

Nelson tune

So after all that still the same crap going on...
So here is what Ive replaced in search of the answer

New wires
New plugs
New fuel filter
New front O2s(rear deleted)

Pretty much everything else was changed in the swap

I stole a maf from my friends truck... no difference

So that leaves the wire harness and the fuel pump as the only 2 things that havent been changed. And the fuel pump was done less the a year ago...

Im drawing a blank, anyone see anything I may have overlooked?

 

I would check your fuel pressure, sounds like you pump may not be putting out enough...

 

That is the game plan for tomorrow, does anyone know the spec... I would assume around 60psi

 

Yep about that..
John

 

Ok well I checked pressure and at idle it was about 40psi and if you let it sit there and idle it slowly dropped. If you rev it it would drop to 0. So I changed the pump and it runs perfect, thanks guys.

 

Make sure you replace the filter and the fuel pressure regulator as well. Damn, sounds like that fuel pump cost you about 2500 bucks! Congrats on getting it figured out.

 

More like 7000, but alot of things were replaced and it was a good excuse to do what I always wanted.