To question #1 -- YES!!! Easier starting, better fuel economy, more power at higher RPM's. Or at least that's what I've experienced.

To question #2 -- Unfortunately, the MSD 6A will need to be coupled with the MSD Tach Adaptor, Part # 8910? I think. -or- 8910EIS (electronic ignition system) they run under $30. Easy install with instructions.

your Mallories green trigger wire goes to the MSD's white trigger wire. Big red to battery, big black to closest ground, small black and orange to the Promaster coil. small red to keyed ignition wire (Usually the same wire that the Unilite is powered with as long as it's a 12 volt keyed source)

I can't remember the rest but I know it's on this site somewhere as well as HybridZ. I can't be the only other one with this set-up. If yu can't find it, let me know, I'll go look at the car and try and make a diagram for ya, but look around here first.

Dave.

Great Dave - thanks. I'll get this laid out and before I tackle this I'll consult with you. Many thanks!