OK, I got the distributor rebuilt and installed and advance works great now. Base timing is at 16, total timing at 36, all in around 2,500. Might be able to take a bit more timing, but feels good. I'll play around with it more later.
One strange issue though - the advance seems slow to come back down and a few times it has sort of "stuck" around 32 (still advances at RPM up to 36, but then only drops back to 32ish). It only seems to do this occasionally, but it some cases has stayed "stuck" even when I turned the engine off and turned it back on. But yet the advance mechanism couldn't be any smoother than it is. There can't be anything hanging it up.
I have a theory that I thought I would run by you all - I replaced the old springs with two replacement springs for this distributor from Mr. Gasket. (
http://www.summitracing.com/parts/MRG-925D). They are the only replacement springs I found anywhere and they are a bit lighter than the OEM Ford springs. So my theory is that potentially the springs aren't quite strong enough to bring the advance cam all the way back at much more than idle RPM (can't explain why once it didn't come back after I shut the engine down
).
Easy enough to test - try one heavier spring, except I don't know which other springs will work since they only list the one set for OEM distributors.
So what do you think about my theory? Any other ideas, anyone have a problem like this?
And, anyone have a recommendation as to which spring kit I can buy that will fit this application (otherwise I can just buy a bunch of them for $20 and see what works).
Thoughts?