so it might be a stupid question but whats the difference between the fc and the fd motors in reference to the short block and internals.

 

The short answer is "everything".

Irons, housings, front covers, oil pan and rotors are different, off the top of my head. Then every accessory (such as pulleys, sensors, intakes) is different as well. Engine mount location is the center iron for the FC 13B and rear iron for the FD 13B.

 

thank you for the answer im still a rotary newbie.