Are you using the new style crossover exhaust with new heat muff? If so, it doesn't align with the way the plans have you build the carb heat intake in the FAB - it also ends up very close to it. Is this the problem you are referring to?
If so, I ended up moving the carb heat control cable to the pilot's side of the FAB, and moved the flapper valve and intake adapter to the passenger side, so it would match up closer. This allows the very short section of SCAT tubing to line up better. I had to remake the steel arm that controls the flapper because it was backwards, but other than that no big deal.
RV-9A - Done(ish) 4/5/16! Flying 4/7/16