Hey guys hows it going. i have run into a problem with my motor swap that i am doing, i am swapping in a 6.0l out of a cadilac and put a edlebrock pro flow xt manifold on it after being told that the stock tb would fit i found out that it most definently will not. now getting a ls2 90mm tb isnt a big deal but the wireing harness conectors are differnt the 90mm is a 6pin and the stock 6.0l is a 8pin.( its a drive by wire )
So if there is anyone that has used this manifold on a 2003ish silverado that used to have a 5.3l if you could tell me what you used for a tb that would be extremly helpful thx.

 

you can use the stock TB ( 3 bolt) on the newer 4 bolt with an adapter plate.

 

Lots of us are running LS2/LS7 TBs on 2003 - 2006 trucks. Google "LS2 throttle truck"

 

Thx for the info guys, does anyone happent o know about how much hp gain i will get if i go to the 90mm over the stock 78mm i am going to school and kinda on a budget right now and i dont want to have to spend 700 bones tuneing it then they say that it isnt getting enuff air and have to spend that much money again.

 

I would stick with whatever TB came from the factory on the motor if the motor has not been modified and needs more air. In stock form I don't think you will see much gain from the larger TB.

 

It is nto stock nemore it used to be a 5.3 i swapped in a 6.0l 30 over bore heads cam new intake nitrous new lifter rockers and everything.