Update: machinist is done, waiting for the assembler to get done with holidays. Transmission 200r4 due to arrive next week. Ski season and awesome snow this year, so hard to say when install occurs.
Held garage night with local VCCA vintage chevy club. We discussed my clunking powerglide. The flex plate where the torque converter attached was really beat up. I've got a new heavy duty plate. The guys said the bolt holes were likely elongated (plate is gone now) and the most likely cause of the clunk when shifting gears. One guy had exactly same issue on his service truck years ago and fixed with a new flex plate.
