leaking rear main seal on flathead- how to fix

have a fresh race built 8ba style motor.have the dry sump pump set 60 psi @fast idle( about 1000 rpm is injected on alky). will get to 80 psi at 5000. Rear seal started with a slow drip, but is getting worst the more we run the engine. Leak is on the motor side of the adaptor plate, no oil in the bell housing. Not use what type of rear seal the builder used. The crank is a merc with 4 1/8" arm. Any ideas??

 

boy that is annoying maybe edit your post and some one will give you a hint about fi xing the leak

 

How to fix leaking seal. Hmmm. Put it a new on. The one you have must not be seated right.