I currently run 3.42's. If I install a 4l80, How much of gear in the rear will I need to change to in order to achieve the same 1st gear ratio? Thanks in advance . I am sure somebody knows

 

I get 4.20's which means you would either want 4.30's or 4.10's

 

This also might help.
https://www.performancetrucks.net/fo...d.php?t=396210

 

Supposedly the higher gear ratio will help the turbo spool better.

 

I have a 60 turbo on a 6.0...I spool @ idle

Thanks guys, I figured 4.10's 'll do it.

 

might want to check out 3.73. most Turbo guys run or wished they ran 3.73 over the 4.10, but one other thing you didn't say, how big of a tire are you running?

 

pretty sure he's still on stock 235/75/16s, from whati remember in one of his racing threads

 

He is right. And there gonna get smaller. 275/55/17 or 285/50/18 or 275/60/16 . One of those in the not to distant future.

 

Keep the gears you have they will make the turbo spool. If you swap to 3.73 or 4.10s it may slow down the spool.

 

same thing i was thinking if anything put a 50hp shot for the hole shot but a turbo likes back pressure,bind on the motor and that will net a better et check out wildracing z71 excab stock motor trans verter ran 11.4x i think he has 3.42 if i remember right