Differences in ECM .. PROM only?

I'm currently looking for a computer for my 95 with Autobahn. GM parts direct only has 1 kind of computer (non-autobahn). Is the only difference in the ECMs the PROM? If I pull the prom from mine and insert it into the new computer will it be correct for my car? Should I get a new prom to go with a computer? It can't be reflashed because its a OBDI.
Anyone have experience with this?

If you will get proper part no, you only need to reinstall your PORM in new PCM. It will light up code 80 most probably but it'll go away after couple hours driving.
I personally replaced my faulty 95 non-bahn PCM with pcm from Caddy STS 4.6. Oh yea. It's same part no., only had to reinstall prom and relearn.
All good.