How many miles are on the transmission? If it is getting kinda old, then I'd say have it torn down and rebuilt correctly. If it is rather young and taken care of, you might get away with the minimum, a TC and VB. How much to spend and what parts to buy is based on your use and hp goals. My trans builder says a auto really ought to be torn down and "refreshed" every 150K or so regardless of how it is performing or how it is used. You will be truly amazed at the difference a good tight TC can make. When I comes to trans, I believe do it once, do it right.