I recently purchased a Superformance with a Roush 427R, the car did not run for 3 years, the car has roughly 300 miles, and the engine is leaking 
oil at the back of the engine between the clutch housing and the block.
I suspect and believe that the rear crank seal is defective.
Do I need to contact Roush for that particular seal, or I can find this part at any good Auto Parts store?
Thanks for your help.