00 Auto with 4:10
 

When is it suppose to shift at WOT. Right now it shifts at 6300. I am thinking it is shifting to late, and It worries me it is shifting beyond red line. Anyone else with a 99+ auto, 4:10 gears, what are your RPM's shifting at?

Without a shift kit or a chip, your tranny is going to shift "later" because the rpms are rising much quicker then with your stock 3:27's.
Lets say that your car commands the shift to begin at 5600 rpm with the stock gears, and by the time it actually makes the shift, your engine is around 5950 rpm. Well, with the 4:10's, it'll command the shift at the same 5600, but the rpms are rising so much faster that the shift might not occur untill 6300 rpm.
Did I explain that ok?
So a shift kit or chip will make the shift occur much quicker and firmer, and the engine rpm will be back at an acceptable spot once the shift is finished.
Fell free to ask more questions because I am not sure if I fully explained it.

That makes sense except I do have a chip installed. Had it put in to correct the speedometer. I am wandering if I should go back and have the shop that burned the chip correct this. Thanks for the reply.

I have 4.10's and a chip in my auto GT and it DOES NOT shift past redline. Get that chip fixed!

Definetly will do that this Friday. Thanks for your reply

Just shift manually. It'll work as a temporary fix except until you need to go into Drive when it goes back into computer controlled mode.

that sounds like it could be several problems (from the computer to the tranny itself) , nothing to do with the gears.

No, Everthing shifts great during normal driving or part throttle. It shifts past redline when I have it floored. Maybe that will help.