Converting BACK from OBDI to OBDII, S52

[Nick's e30]

Hey all,

I recently picked up a complete S52 swap, all set and ready to go for an e30. There's a few things I want to fix on it; the main issue being the shoddy wiring harness which gave the PO all sorts of dash lights that shouldn't have been illuminated.

I'm considering a swap back to OBDI. Is it worth the extra few horsepower at this point since I'm already OBDI and it ran perfectly with OBDI?

What would be needed if this was to be worth it?

Thanks for any info that can be provided!

[ClausE30]

You can retain obd2 and still run the obd1 intake manifold. The manifold is really the only gain. I have an obd2 s52 and being able to see diagnostics on my phone is far superior to anything obd1 has. Surf the threads in the swap section of R3V, all the information is there and it was the source for myself completing the work by myself