I have a new Lycoming 0-320, Catto three bladed prop (specified for my 9a with 160 hp engine) one Slick Mag and one P_Mag. The engine reaches a maximum of 2410 rpm full rich while burning 11gph. TAS is less than 140 knots without pants and fairings. (About 20 knots less than I'd expect)... I've checked throttle and mixture linkages for full range of travel. I plan to call Catto to ask about the pitch of the propeller but is there anything else I should be looking at?