Torque Converter Questionnaire/Laundry List

Mistabreeze said
It's a standard rebuilt 727 with red clutch discs. It's still automatic, not mrvb. Not sure if it's a lockup or not? Is there anyway to tell?

run the #'s on the pan. lock up debuted in 1978

or, if you have the torque converter out: straight input, fully splined to the end is non-lock up. a stepped input with about 1/2" on the end machined and 23 splines is lock up.

hth