Identify the exact engine/block

I would appreciate if anyone here can point me in where/how to identify the engine in my 87Civic..it may be a rebuilt/different one..I cannot get new starter motors to work.
The number on the back of the block is C15A?-12U7635.
Thanks for any and all considerations, sincerely...G

The engine ID should be on the left side of the front of the engine (if it's still a D-series). It will be stamped into a 1.5" square, just to the left of the exhaust manifold. Please post the # when you find it and I (or someone else) should be able to tell you what car it came out of.

I just remembered that CVCC wagon was kind enough to post this a while ago.

http://www.automotiveforums.com/vbulletin/showthread.php?t=275754

You should be able to use this to identify the motor in your car.