Trying to figure out what block I have

[faster_daddy_faster]

I have a block that I'm rebuilding that I got my hands on in a lower unit package deal purchase and I belive it's a Merc/Mariner 2.4 200. The only ID# that I can find is in the plug on the top of the block. The plug reads, A very large M and the #'s B169563. If anyone can help I'll greatly appreciate it due to having to buy a crank and I want to make sure I'm getting the right one.

[O/B Dude]

Sounds like you have it apart. Measure the bore. 3.5" for a 2.5L and geez, I can't remember the size on a 2.4 but it will be slightly smaller. A 2.0 will be noticeably smaller.

[O/B Dude]

I ran the number. Came back as a Mariner 2.4 200. Merc parts express doesn't show a year but they are all pretty much the same except for the 82 model year. That one was the same as an 81 2.4 225. Different porting, head bolt pattern, etc...

[sosmerc]

My book says 1987 200....micro card #64, parts list 90-821303. That would be an oil injected, 2.4 litre.