Port my current M1 single plane or install the RPM Air Gap?

Rat Bastid said
Use the M1 and forget about the carb flange.

If it bothers you that bad buy a Magnaflow anti-reversion plate and make the plenum match the gasket that comes with it.

I was hoping you would reply. Thank you for that nugget of knowledge. I've never heard of anti-reversion plate.