Hi Jeff, yes this was a real bugger of a job. I did hire out, to a Man that is well versed in Old Mopars, and is fussy in his work.
The problem was this, on the long block engines, the 2 center studs, that are about 3 1/2 inches long are just about always bolts, so what do you do.
By the time you try and heat the head of that bolt, the surrounding cast iron sinks the heat.
So what was left was 1 broken stud, the 2 broken bolts, all broke off flush to block, not much option there. I do fault him on breaking the stud, he should have spent possibly a little time applying heat on it first, but he did not.
The counter weight and bi-metallic spring, spring ws tight, and did not relax when the engine got hot, it was tight enough that when revving the engine, the counter weight would not spin.
This at first caused me some concern, thought perhaps the metal damper was either rotten or not on the heat riser shaft. I confirmed this by pulling off the spring, and held onto the heat irser, revving engine same time, there was quite a force created by the exhaust to force the counter weight forward, so it is working fine, the spring is the culprit.
Last night I stretched the bimetallic spring a bit, and it wroked well, I may have done it a little too well though. I do not see this spring expanding with heat, so will finda another.
I would venture to guess if the bimetallic spring is tight, but allows counter weight to move when revving a cold engine, and then allows damper to open fully once the engine warms, all may be well. If the counter weight returns to the cold position once engine cools and spring contracts, all should be considered functioning and well.....