MSD Coil differences?

Blaster 2 is good for just about anything. The SS is not for all boxes and you could burn one up in a hurry. The SS has very low resistance and needs the right box to run it. Its not a good choice for a street machine or anything that does not turn a lot of rpm(less than 6500).

What box are you running? If its a 6al go with the blaster 2.