Need help sleuthing correct part number: TCS temp sending unit

[DeadheadNM]

I've hit a wall in trying to locate the correct part number or equivalent for the temperature sending unit for the transmission controlled spark system for 1972. It mounts in the RH cylinder head and looks like a temp sending unit but has a SINGLE spade-type harness connection. OEM correct example is shown below.

The parts catalog lists group 2.408 #6489600 trans spark control (temp override) but that part number returns units that have a double spade harness connection (example pic below found here: https://www.ss396.com/chevelle/GAC-6...hevelle&year=0 )

Can anyone help with a part number that's correct for this TCS sending unit?

[60case]

I removed one from a set of 1972 blazer heads. It is stamped AC 82B. It is a single spade connection

[Steeveedee]

What I remember from those days is a thermostatic vacuum switch that was installed in the thermostat housing, not something installed in the head. I'm not contesting your reality, just posting what I recall, 48 years removed. Can you post a link to a schematic for the TCS system for '72? I'd personally toss/bypass the parts, but if you're looking for total originality, that wouldn't be the answer you are looking for. It was used for reduction of oxides of nitrogen, btw. It doesn't help with mileage, except for the part where the engine would warm up faster due to the reduced timing advance until warmed up/and in high gear.

[DeadheadNM]

Originally Posted by 60case

I removed one from a set of 1972 blazer heads. It is stamped AC 82B. It is a single spade connection

That’s helpful - I’ll chase that lead. Thank you.

Funny searches using those AC numbers also yield a double spade sending unit like this one here: https://www.carid.com/oe-replacement...r-82b-232.html

[DeadheadNM]

Originally Posted by Steeveedee

What I remember from those days is a thermostatic vacuum switch that was installed in the thermostat housing, not something installed in the head. I'm not contesting your reality, just posting what I recall, 48 years removed. Can you post a link to a schematic for the TCS system for '72? I'd personally toss/bypass the parts, but if you're looking for total originality, that wouldn't be the answer you are looking for. It was used for reduction of oxides of nitrogen, btw. It doesn't help with mileage, except for the part where the engine would warm up faster due to the reduced timing advance until warmed up/and in high gear.

Steve I’ll follow up with a schematic for you in a bit but the above photo is of a correct part that I personally removed. The part you describe I suspect is 1114451 vac solenoid and is different. I’m one of those tormented souls who like it to be as it was from GM.

EDIT: added schematic

[68 P.O.S.]

Is this what you're looking for? https://www.classicparts.com/1971-75...ctinfo/53-608/

[DeadheadNM]

Originally Posted by 68 P.O.S.

Is this what you're looking for? https://www.classicparts.com/1971-75...ctinfo/53-608/

It's not but I appreciate you looking, thanks. That's a transmission pressure switch used for the TCS but not the one correct for 1972 TH350, which the parts catalog shows as #3996287 but if anyone would want get one I'd confirm harness connector shape (6462549 is listed for 70-71 TH350)

[Steeveedee]

Originally Posted by DeadheadNM

Steve I’ll follow up with a schematic for you in a bit but the above photo is of a correct part that I personally removed. The part you describe I suspect is 1114451 vac solenoid and is different. I’m one of those tormented souls who like it to be as it was from GM.

EDIT: added schematic

OK, thanks. I guess I must have been channeling a different car line.