Its a 87-93 700R4, GM calls them a 4L60.
The plug is for the TCC, It Needs to function.
The "Vette" 700R4 is not that different..."093" 2nd piston, Different 3-4 shift valve, & different governor calibration/diamond shaped weights.
Its imperative that the TV valve cable is set correctly.
Search this forum for lock-up & TV valve set-up.
I instinctively roll my eyes when I hear the term "Vette"
