What dominator for my build?

Hey guys I am building a 466,approx 13.5:1, a-429's (ported but unknown #'s) mafia intake, unknown solid flat cam(going to call someone on here and get a custom grind) this is a max effort deal going in a fairly light mudtruck. I am looking at used dommys and coming up with 8896's or 4375's my jegs cat says 8896 is for single and 4375 is for duals and I was wondering what the difference between the two was.

I would contact Patrick at Pro Systems, or Phillip and do custom deals.