I bet most of us could do a few simple tests on site and have a solution in minutes but doing it this way, more info is ALWAYS better and really easy to get.
I appreciate your optimism..
Here's the specs.
'67 satellite 727 auto. 323 rearend gears.
Recently rebuilt low comp (dished pistons) smog motor. headers, comp xe262 camp, performer RPM intake, edelbrock 1403 carburetor. Runs very well when timing behaves.
Intermediate shaft is new, and distributor has a shaft collar to keep from bouncing. Had a serious issue with erratic (varying by almost 5degrees) timing at idle until I installed the shaft collar.
I have been chasing detonation issues last few weeks that I thought were due to a too-fast distributor curve that was putting way to much timing in from 2000-2500. In reality, now I realize every time I set base timing it would advance past that by 5-8 degrees. Best I can tell, with an actual 12-14 degrees base timing the car runs fantastic on 87E10. It only starts rattling from 2000-2500 under heavy load when base timing is up to like 18-20 degrees.