Hey 'Reserved', I hope you got this sorted. I had a similar situation recently and had no idea if my issue was this, that, or the other in my electrical system. After days of racking my brain over many weeks inbetween, a fellow club member (thanks Vince) helped me out. There is great comfort in having a fellow rev head, look bewildered and say, "I don't get it... It should start". Back to basics (again, and again), and narrowed down to an inconsistent positioning of my Distributor shaft (springs/clogged/other??). I've imported the MSD from Summit cheaper than I could get it from Rocket. It's a bit more mucking around, but hopefully worth while with regards to reliability.
Just though that I'd share to thank a fellow member and point out that (although I'm a rocket fan) there are alternative source options to the MSD 700 tach drive unit from Rocket.