RE: Evolution 60 or Jet 53
Jett also has one other great engine besides the dedicated "race engine" and that is the Jett 35.
I have the rear exhaust one and it will spin a 8x7 at 21,500.
Jett also makes a 40 in a 25 size case that will spin a 10x6 APC easily at 15,700. This is stronger than any stock 40-55 size engine.
I need to buy one my self.