The 4R70W is a PCM controlled transmission. The programmed shift points are based upon how long it take the transmission to actually change gears and at what RPM the gear change should be completed. When too low of a gear is used this causes the RPM's to rise faster than stock. The net effect is it still takes the transmission the same amount of time to change gears. However the RPM's have risen more/faster due to the lower gear. For this reason it's sometimes necessary to adjust the shift points so that the gear changes have completed at the same RPM.
Thanks for that information. I will run it by my mechanic and see what he thinks. Going to go with 373's I think the 411's are to much for that car and how I am going to drive it.
I’m still wondering how your car with LSD is doing. Did the psychedelic paint job turn out like a flip paint or a 60’s VW bus?
(There’s a reason the term Posi is borrowed from GM.)You have reactivated a Zombie thread.
The threads that show up at the bottom or show up in a search should be date checked. Now if you have experience to add for future searchers, maybe it’s a memorial thread.
