Scott, that's interesting info from MSD, 'cause I found the same thing inside my distributor, and others here in the local club have had a lot of corrosion-looking stuff inside the caps. Gonna drill mine ASAP, though it's not as bad as yours is/was.
And on a followup note, I had earlier posted that I had 140 psi across the board on my motor...Cracker's reply comment hurt my feelings (
), so I had the cam dialed in, and found two things: first, my GAUGE IS RONG (my motor guy got 165 psi before he did anything...not all that bad), and second, he got 185 psi for the lowest reading when he finished (better). I'm picking it up this pm, so I'm expecting a noticeable (seat-of-the-pants) improvement.
On your timing, I think you're on the right track with the springs, bushing and settings. Let us know how it goes.
BTW, you can use a 55 Chevy standard distributor cap on the MSD billet in an emergency (or permanently?) .