electronic distributer swap question ( a dumb one I think )

Ok, here's a REALLY dumb question! LOL

-- How do you know if its a points coil or ecu coil?

I bought an MSD Blaster 2 coil and intend to use it on my 74 318 with electronic distributer, a new electronic wiring harness from Bill Evans and a yet-to-be determined ecu box...I figured an orange box, or someone suggested using a aftermarker stock replacement from Wells.

Thoughts??