Is a 78 351M rear main seal one or two piece, any special tools? My engine is already out.

 

Two piece. No special tools required.

 

do i have to drop the crank out? i've heard you can replace them without droping it .

 

Nope, No need to remove the crank. The rear main is a 2 piece. You might want to check your bearings while your in there

 

I replaced one on a friends 76 - 351M back around 1980 and the rear main seal was a rope or wick type. We couldn't get the top half out. Did ford use rubber seals sometimes also? Can you put a rubber in place of a wick style? I was just wondering.