I'm pretty sure it's a two piece rear main seal as the serial number is for an '86, and I don't think Mercruiser went to 1 piece seals until 1990? That's important because both of the rear sump oil pans I have are for the two piece seals. It came with a 25lb flywheel which is drilled and tapped for a pressure plate, but it will need to be surfaced as it is currently black paint on the unsurfaced casting. This thing is amazingly clean inside!
