A “proper” lock up converter has a clutch in it that’s activated by the transmission.

You need both a lock up converter, and the trans to go with it.

So...... no one running a regular 727 or 904 is using a lock up converter.

Unless there’s some current technology for those transmissions I’m not familiar with.

68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads