Just got done building my predator motor with: 18lb springs, port and polish head, 0.16" copper head gasket, #39 jet and 140 emulsion tube, NR racing marine cam, robertsons torque tube, and RLV modified exhaust. The thing is straight mean. Its on an sps kit with a 7-1/2" prop and a 1236 flat jon with no middle seat. Spins that prop with ease. My old briggs wouldn't get up to rpms with it. So I want to prop up. 9" to 9-1/2". What yall think other than to get rid of that trashy sps kit? I know it sucks but i like it.