Hands down the ART Carr high tech valve body kit . It is superb, I love it ......1-2 shift is more aggresive than stock but not harsh, the D-OD is alot firmer and the tranny will be able to shift to OD at WOT where as stock it will not. Has good instructions also. This is what I installed in my 87.
On the cooler yes gat a aux. one it is a must. The #1 killer in alll trans is heat, period. Get a satcked plate design and not tube and fin. B& M makes a good one...I would get tghe 28,000 and not look back.
Good luck
Well if I am there to replace the TCC think I will install a shift kit too. B&M shift improver kit set to stage 1(heavy duty ) or stage 2(street or strip). I am thinking stage 2. What has been your experience with this shift kit? This kit looks simple to install. Better kits out there? And a tranny cooler kit too. Mark at PTS Extreme assured me a good cooler is a must for longer life. 
