Are there any differences between the B16A1, A2, A3 blocks themselves?

 

Blocks? No. The cams vary slightly from version to version.

 

Yeah, I know there are tons of differences in the heads.. cams, lots of OBD 0/1/2 stuff .. I just wondered if the blocks were the same. I want to build an OBD 2 unit, and thought I could save a few bucks by just using a B16A1 block and sticking an A2 OBD2 head on it.

 

No important differences in the blocks. I wouldn't rule out minor changes.