First off, with the Byron fan setup (pusher), you will need a LARGE HEAD engine, not the small head which is used with the tractor fans such as a Dynamax or Ramtec fan. This is due to the engine needing extra cooling from not being in the airflow provided by the fan. You can easily convert your small head engine, however, by purchasing the large head. Also check into the bolts available from JMP that will hold much more reliably than the stock ones when you make the change. Good Luck.