I have a stock 6l80 in my truck and the truck makes 700rwhp, I beat the shit out of it and its fine! It has a 3400 stall and a little trans cooler lol. Trucks been 11.1@120

I doubt i will ever seen anything close to that.... Be happy with 400-425 rwhp out of the yukon....

This is very reassuring.

I can handle the milling part... thanks for the heads up!

RT

Was your trans tuned?

You obviously have better luck than me... My truck has 7000 miles on it and Black Bear has tuned on the trans for months and we can't get it to shift firm at all. Justin actually has told me that my tune has almost twice the pressures that all of his other tuned transmissions have and that the customers complain that there trans shifted like it was going to break a u-joint. So I think the valve body has a stuck valve or one of the apply pistons are cracked, or one of the solenoid laminates are torn.

I have spent a really long time fine tuning my 6L tune. I feel I got it to the point where its spot on. if anyone is interested I do not mind sharing.

how hard would it be for you guys to just swap to a 4l80e? I fuckin hate 6 speed autos...

Care to elaborate.... Considering the vehicle i want to swap the 6l80 into is my family/road trip vehicle. Id rather have the extra two gears....

Output shaft
 

Does anyone have a good part number for the 4x4 output shaft, transtar lists 3 different 2wd shafts for the 6l80 and one 4wd for the 6l90....