Quote Originally Posted by sleeperred90tgp
Mike if you have a th350 or 400 there are no provisions for a lock up converter. There 3 speeds only. If your looking for a trans with lock up then look for 200r or 700. They have the lock up converter your talking about and yes there are kits to switch to lock up, ( click the TCI add below)there are also hydraluic kits that will lock it up with no switches. Great product, I have one and it's far superior to switches.

Jud
Jud,

You may want to reconsider that statement. This has been posted on several technical sites on the net:
The HydraMatic 350 transmission was prevalent in nearly all GM, rear-wheel-drive cars and trucks through 1981. It was typically paired with Small Block V6 & V8 engines. It was produced as the TH350-C through 1984. This later version had an electronic lock-up converter to increase fuel-efficiency at cruising speeds.
That being said, since the TH350C is not an overdrive trans, the lockup is only there for gas economy. You can drive it without connecting the lockup.