I bought a B16A for my civic, the block says B16A, but i believe it is a B16A2 out of a 1992 JDM Civic SiR-II. Are there any ways to find out what motor i have exactly? because my friend's H22 actually says H22A4 on the block, so shouldn't mine say B16A2?

The Valve cover says 1992, and i believe that the only B16A2 made in that year that was OBD1 was a Civic SiR-II, since the Del Sol DOHC VTEC came out later...

 

JDM spec motors only came with a letter after the numbers. for ex: b16A B18c H22a
usdm motors came with numbers after the letters
B16a1 B18c1