Originally posted by mtx3racer
What is the difference between these two .21 on road engines???
.Rear Exhaust .21 PT-21 R Race On-Road
.RX 21 R1 on road
They difference is that the PT-21 is the TOP Version (Black Head)
and the RX-21 is the NOVA Version (Purple Head). Its mainly
cosmetics that differentiate the two but they are the same base
motor (Stock to Stock).