You never know. A good friend of mine ordered a TH-350 from TCI. It lasted for less than two weeks behind A low boost 350 with a cam, stock heads, and a 3000 converter. He ordered a book, a video and a rebuild kit and rebuilt it himself. That was the first time he had ever saw inside of an automatic transmission, but that was five years ago and it's still going strong.

I'm not saying that TCI builds a bad transmission. The TH-350 and TH-400 have been used in race cars for so long that most areas should have a competent builder. It would be much easier to deal with a local builder if something does go wrong. Especially when their reputation and livlihood on the line.

 

Well, I know he will stand behind his work. It is just a matter of pulling it out and taking it to him. I am going to try to get with him so he can ride with me to see what it is doing.

 

most tci trannys DONT have the upgraded parts in them that are needed to handle power.
if you dont order their competition unit, or a custom built one from them, the sizzler, street fighter, and super street fighter arent going to hold up in a cammed or headed ls1.

if its only lagging on the shifts on WOT, id say there is a line pressure problem. possibly a weak front pump, or something jacked up in the valve body.
good luck.

 

that why I bought the competition unit