At what hp does the stock input shaft brake on a 48re? Will leaveing the line at 1500 rpm in 4wd with a smarty brake it or will the tranny be ok?

 

Input shaft might hold if its stock. Its the torque converter and rest of the tranny that will slip if its stock. Stock input shaft can hold a wide range of horsepower - all depends on how hard you put it to the ground. 1500 RPM in 4WD will be hard on a stock tranny either way you look at it. even without horsepower upgrades.

 

i have a tranns go shift kit and an after market torque converter. How much will that the tranny not slip?

 

Not too much your flex plate will probably flex enough not to break your input shaft. Once i installed my bd flexplate i broke my stock input shaft twice, both times hitting small bumps in the road at wide open throttle!

 

ok thanks!