John, I take your point about the Crane seeming like overkill just to drive an MSD box, but you already have it... certainly there's no technical problem with using it.

I've got a related project coming up when I get a few spare bucks to throw at the cars. The MPPE falls on its face passing 6000 rpm, and by process of elimination I'm 98% sure that feeble ignition is the culprit. I'm running a Lumenition system, which is essentially a Brit version on the Crane -- except for output, as some research now shows.

I plan to use it to trigger a GM HEI module ($35), which in turn fires an MSD Blaster 2 coil ($40). That should keep 'em sparking under load, methinks.