Th350 or th350C?

[V8 Rumble]

The th350C is for lock up converter not that it includes one.

 

[565bbchevy]

I have a 350C that came with the 83' Lesabre that I took the drive train out of and they had a 12 volt toggle switch to lock up the converter and a big red indicator light mounted to the dash , it was rebuilt with a shift kit and it shifts really firm but my 86' Regal came with a very good working 200R4 so I decided to just keep that.

 

[olds307 and 403]

I am betting you actually have a TH250C. Look for a stud near the cooling lines. I am pretty sure there is differences in the valve body too.