Good info Jerry, but I wonder if distributor nominal cam angle changes between small cap and tall cap distributors, all your info looks like the small caps. It is pretty much impossible to set your points correctly ie .016-.019 gaps and obtain some of those huge dwell angles that you published on the tall distributor. This is my opinion only but I have spent some time playing with point gaps and dwell readings. I'm going to head out to the garage and start looking at the distributor lobes between the tall and short designs to see if they differ.

Last edited by sstock; 08/29/2019 11:24 PM.
1953 Chevrolet 3100
261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done
In the DITY Gallery
Video of the 261 running

1964 GMC 1000
305 Big Block V6, sm420, the next cab off restoration