Jerry, this is a 250 in engine.
The spring on the manifold heat plate is help warm up the carb and manifold in cold to cool weather. Once the engine is warm, it's relaxed, it's only working when the engine is cold. It's should be fixed for better start ups, but for now, most likely not the problem.
The advance pulls the rod and plate towards the vacuum pot, you should be able to suck on the hose and see it move. The hose could be direct manifold vacuum or ported vacuum. Direct manifold vacuum will pull the advance in as soon as the engine starts, ported vacuum will pull the advance once the throttle blade is opened. Look to see where the hose hooks to, above the throttle blade or below.
