After finding the code and digging around, I found this is a GM8 stock Turbo 400 Torque Converter - the car originally had a GM3. TC rebuilder (PDQ) says they're the same except the GM8 uses metric bolts. Has "low stall speed" which may be 1350-1500 rpm. It's fine for me as I'm trying to get the car basically stock for now - going for efficiency and decent power.
Stall speed is low, but I had a stock 70 455 GTO which would have had a GM3 Torque Converter. The biggest problem was non-positraction - the power was there, but the tires wouldn't grab. I need to learn more about stall speeds. Main thing is transmission shifts into gear, drives, and shifts between gears fine - the guy did a great job rebuilding it.
After 14 years of sitting, it's nice to have this car back on the road. It handles and drives like new... Lubed front end - ball joints were new but all boots had stiffened/rotted (one completely gone). Polyurethane stabilizer bar bushings held up great. No squeaks or rattles, which surprised me.
Only "problem" is setting up a 1975 Grand Prix HEI distributor to run with this engine - there is no detonation. Will start another thread about this.
Oh... also learned there's no problem with engine turning while torquing the TC bolts.
Turned engine with breaker bar on crankshaft bolt (easy with no fan/belts) until could access TC bolts on right side (opposite of starter). Got them all started/finger tight, then torqued - Wallace says 35 ft lbs. If I pulled at a right angle to a line running to crankshaft, while torquing, the engine didn't try to turn. I was thinking of having to lock engine to remove crankshaft pulley bolt (these days I use an electric impact driver).
Last edited by 60sPontiacs; 12-30-2017 at 09:11 AM.