MSD 5520 any good?

I purchased an HEI set on here and I am looking to max the benefits. I don't have the cash for a new 6 or 7. How will this work with the HEI? Currently running factory electronic ignition on a 9.5:1 318 +.030. I want to install the HEI and the spark controller at the same time and found one for $140 new.