Keisler Tremec TKO 600 5 speed

If you have problems with the TKO shifting, call Walt at Promotion Performance. He took the time to explain the internal upgrades that help with high rpm shifting up to 8000 rpm. I have not done the upgrades (not running yet, waiting to see if I have a problem with it first), but I did buy a girdle off him for the TKO that is supposed to help avoid gear walk (?). $169. Cheap insurance, in my book. He's got TKO600's running 9.0's at 150+, and said that's about the limit of a built/modified tranny.