Yeah this thing is really hard to see. I’ve never seen mine because it’s so deep down there. Here are some images clipped from eBay auctions for 1985 engines. It is on the engine not the trans. But it is really close to the boundary that’s why we say on the bell housing. Good luck.
Maybe you can use the 6000 imp gauge and a green tach amp board if you don’t have this sensor. Meaning you can grab the signal off the front sensor and use a gauge off an 82/83. Not optimal but it may be easier than figuring out a sensor for an old om617 block. You may actually need Frank Reiner’s 6000 imp gauge.
ETA - yeah this makes sense. I think BillGrissom told me the ring gear has 140 teeth and provides the signal to the pickup coil. That means it has 140 pulses/revolution X 6000 revolutions/minute / 60 seconds/minute = 14000 which is the full scale impulses/sec (Hz). That’s what is stamped on the back of the gauge. So I think that little sensor just reads the teeth.
