Do the 3:08's have to go???

[ERASER5]

My vote goes to the distributor. Check the vacuum advance plate for movement as well as the mechanical advance movement. Been there, done that. Twice.

On the engine forum Billa has a very helpful write up for setting timing. It explains hoe to set your timing at 3000 rpm instead of 800 rpm. This setup made world of difference to my engine, that is after I swapped out the non-moving advance plate distributor for a properly working distributor.