[dohcrxl]

Not sure why the GSR head is on the B16a block. Does it increase the horsepower?

It's been a long time since I've looked at compression ratio and flow specs on various heads but no, I don't think there's any big increase in HP. In fact it might even be working backwards to put a GSR head on a B16 block.

What would this motor be worth if it is in good condition?

Tell you the truth, I'd stay away from engines that have been mated and remated with other engines. You can never tell from the outside in if someone snapped a timing belt by over-revving the engine causing internal damage.

What transmission and ECU will I need for this motor?

You can use any cable actuated B-series transmission. If the engine is indeed obd1, then an obd1 GSR ecu would be best.

I have tried to research the OBD1 but I am yet to grasp what exactly it means. How do I know which one will work in my CRX.

If you're talking about which ecu, then it's not a matter of which one will work best for your CRX but rather for the engine that's in your CRX. If you're asking whether obd1 or obd2 is best for your CRX... well actually the answer doesn't change.

Word to the wise: unless you can find someone who is very well seasoned to this stuff, I'd keep away from that mismatched engine. Just sounds like trouble to me. I could be wrong but you might be inheriting someone's nightmare or their "beat the crap out of" left overs.

-Heu