out your clutch sooner than normal. because when you keep your foot on the gas and let out the clutch to shift it picks up R's quickly and as soon as you let off the clutch, its spinning preaty fast, even though its only 1-2 seconds. As long as you dont miss the gear,:bah: it will be fine on the tranny.
Sorry about any confusion I may have caused. I have a 4 spd automatic. When I say power shifting, I mean shifting manually from 1 to 2 to 3 then to drive on the console shifter. By doing that, it's a genuine 1st, 2nd and 3rd gear, and I can bring the RPMs higher before shifting. Is that bad for my tranny or any other part of my truck?
I do that in my impala all the time. It has a turbo 350 with B&M rebuild and shift kit, wwith a B&M fquicksilver ratcheting shifter. Its made to do that. Maybe you could get the B&M electric shift improver to help with the automatic clutch slippage, so it will grab easier when you do shift it manually. But it wont hurt your tranny. Its like holding the throttle down to the floor until the kickdown makes it shift.
Manually shifting a stock auto can be a dangerous thing for the life of your transmission under certain circumstances. If you let the motor rev too high, bad things can happen to your valve train. The stock autos were not designed to run at high rpms for extended periods of time. Quite frankly, they overheat. Additionally, "downshifting" your auto to get that "woooooompppaaaaapapapaaa" sound can also hurt it.