Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Morgan need to give the new Plus 4 more power

My Plus four figures. M16 engine. Advanced ignition, reworked Omex 710 (by Omex) s/s manifold straight through one box, ITG filter. No changes to cams, no tb's; worked on by Mark Adams. Fifth gear at 2000rpm =60mph, 3000rpm=80mph.Second good for 72mph,third for 96mph. Step forward chunky for further advice please.