I just put in a Pro 5.0 shifter on my Tremec. Like night and day! The Tremec seemed to shift a bit rough like between 2-3 and 3-4. Would tend to hang up a bit also when shifting quickly. I tried several types of fluid but that did not improve it that much.
After installing the new shifter I was amazed at how smooth the shifting is now. Shorter throw too.
Shifter was 165.00 without the stick.
http://www.pro-50.com/
Roscoe