Hey guys,

I'm unsure as to what torque converter I have on hand. Help identifying is appreciated for those with high confidence. Thanks.

• car is a '70 Cutlass SX
• TH400 trans
• Limited Slip 3.23 rearend
• I don't see any serial or other stampings; however, there are some sharpie pen markings - "C9", "75", "3"

 

Those look like junkyard markings for when they place them on the shelves for identification later.

I'm not sure I understand your question. What is it you want to know about the converter?
It appears to be a Chevy converter because I see it uses nuts and bolts to attach it rather than just a bolt into a welded on boss. It could also be aftermarket as most of them attach this way also.

 

I have no idea what I have, therefore, the info obtained in this thread will be helpful to determine if a replacement is needed.

You are correct in that the torque converter was attached to the flexplate via bolts with nuts. So, all stock Olds torque converters (at least from the early '70s) had welded in bosses? Thanks for the reply, btw.

 

I'm not absolutely positive about the welded on bosses. I'm just going by my experiences and the cars I've had. TH350 and TH400 use the same non-lockup converters so that converter could have been out of anything in the GM lineup with either of those transmissions. My only problem with converters with those large flanges is sometime they interfere with the flexplate weights.
If you measure the diameter of that converter it should be in the 12-13 inch range which would more than likely indicate a stock converter. If it's 10-11 inches it would be aftermarket and have a higher stall speed.

 

Yes, Olds style converters have the welded lugs.

I thought the TH350 converters were smaller diameter than the TH400 converters. I remember back in high school ordering a TH400 1800 RPM stall for my '70 Supreme 350/TH350 and it was larger diameter than the original converter and used the outer mounting holes on the flex plate. Folks at the time told me the factory TH400 converters were larger diameter (13"?) than the TH350 converters (12"?).