If you want to run horizontal induction and the Sam James cowl you need either an M type hub or a standard hub with a 2.5" prop extension. Prop supplier has said this doesn't impose any restrictions, engine supplier (Aerosport performance IO-375) isn't saying anything. He forwarded it to the tech department and a month later still no reply. Anyone running a Lycoming or clone with the Sam James long cowl care to chime in with some knowledge?