Keep something in mind, you have a 65E tranny and a heavy *** Denali XL if you push the boost to high the trans. is not going to like it..... At least do a shift kit and servos, however at 8-10# boost with a intercooler that is still going to push it. Wait, I think the XL's have the 65E? ? ? Dont they?

 

With 8-10lbs intercooled boost you better plan on doing something to the tranny if you are going to Drive it everyday at those levels. You have a 65E tranny and a heavy *** SUV that will have a decent amount of Power, 65E's are not the strongest.

 

Pretty sure. I think you dont get an 80E until your in a 2500 and/or HD series. 8-10psi is good for a DD if the tune is perfect. Any amount of boost with a crappy tune will net you broken pistons.

 

I think anything over 10psi things start to go wrong with the engine from the history of installs here, turbo or supercharger. I know there is more to it than that, but that seems to be the threshold of issues arising. If you plan on reving it a little higher than Allen will tune for with the stock valve train you will need better valve springs. I've thought about this myself but wondered how much it would really help. The second to third shift in these trucks really drops the rpms down a lot. First to second if where the real fun is.
What have you done to your trans to help it last?

 

Right were I would like to be, the difference between 1.5 and 4.5 was like night and day. I can't wait to see around 8lbs.

 

From what I was told it's the 65E, it has the tow button on the gearshift but I don't think that would be reason for the 4l80

 

Nada, I have had a few friends who both replaced their trans with no mods. One had a 99 suburban and the other a 2002 suburban. I have always been scared about these allison trannies.

 

If you had an Allison you wouldnt have to worry too much.

I'm on my third tranny in 18 months. I was pushing 9psi, now 7psi. One was stock the second was a "built" tranny the latest is a FLT Level 5.

 

That's what I was afraid of having to do. This project was supposed to be a little extra ponies on the side with a bolt on kit. I would sit and look at everyone's signatures and see all the damn mods thinking that would never be me. Now I see my kids college fun will be sucked dry before I get this thing the way I want it.

 

It never really ends. It's like crack. I think I have $20K in mods. This does not count the price of the Tahoe. There not all performance. About $8K are Rims/stereo/TV etc...

EDIT: I just pulled up my "Mod Sheet" With the updates I am sitting at $28,904 in mods. Wait......