Check the quality of your points too. I chased my tail with an inferior brand new set of points. Went and purchased another set from another source and compared side by side and spring steel on the set I was using was not as thick and strong as the newly purchased set. It wasn't keeping enough force against the contacts to reliably make/break. I would go from running great to misfires to no spark at all to misfires to no spark to running great to misfires.....it was like chasing a ghost. I also find TDC on #1 the old fashion way. I stick a wooden dowl rod in the spark plug hole until the piston pushes it all the way up. I peep in the hole and rock it slowly back and forth and watch the piston top out. Turn the dist. to line up the points for #1. Run it for 30 minutes, check valve lash, then set final timing via the vacuum draw and a tach and dwell meter.
