RPM

6400 RPM: Stock engine

6800 RPM: A12 GX Engine

7000 RPM: Aftermarket racing valve springs are needed

8500 RPM: To raise the rpms, we first added a larger oil pump.

9000 rpm: would require worked rods with better rod bolts (or at least new rod bolts all of the time).

9500 PM: RWhen we switched to aftermarket rods we could go to 9500-10,000.

10,000 RPM: Next we found the valve train weaknesses. Make sure to replace the rocker threads with steel inserts. By using rocker tower studs; or going to 10mm bolts, 10,000 was fine with the A12 (9200-9400 with the A14 and A15).