I have been building nothing but performance automatics since 1977, and every transmission I build uses the Trans-Go Shift kit, Performance Shift kit, and/or related products. There are many other things that need to be done to make the 700R4/4L60E a "good shifting unit" that will last. If you have success 'without" the Trans-Go Shift kit, great. Out of all the teardowns that I have done, B&M & Art Carr units are the worst I've seen. Stock units are the next worst. True. I have seen units come in with Trans-Go Shift kits installed that were burnt up, but found in most cases the unit wasn't built right to begin with (so the Shift kit was not going to override bad work), or the kit was installed wrong. You would not believe the stuff that so-called perfromance builders do to these units, and they call it "High Performance" and charge high prices for it. You get a nice expensive sticker for your hard earned money and not much else. If you want to see what I use in these units, go to www.pro-built.net If you have any questions, feel free to call or email me. Glad to help.