Very interesting dyno results, your engine is very similar to mine (YS 400, .040 over, 16 heads, 9.5-10:1, SpeedPros with 14 cc dish, 068 cam) biggest difference is my log exhausts, and Q-jet I think, not sure how 72cc 16s flow compared to your heads. I'd be very happy with 375 hp.
Yours sounded great at idle too. I will also be very interested in how you think the FI behaves in everyday use.
You seem to have this whole car building thing down pat