So at the end of the day you decide to go w/an MSD box 6A or 7AL (limiter) I just want to point out that Summit has the identical unit, made by MSD, does everything the same as the MSD control box, for $75.00 less on A-Tech. We've had no trouble with them, of course it says SUMMIT on the box, not MSD but apparently the guts, & wiring diagrams & functionality are all synonymous.
Also note there ae a few RTR distributors that will work in the Pantera engine bay. Ready To Run distributors require ~no Multiple discharge Box~ to run, only the dedicated coil.
Finally, the best bang for the buck monetarily & quality wise is the Pertronix RTR distributor using their own dedicated coil. Easy plug & play.