if its for a cvh mate the best bet is a decent exhuast manifold and system, overbored bottom end, big skim on the head with very mild porting. fueling wise a DMTR twin choke webber is best bet as 40s only give serious gains with big headwork - which will ruine the torque. port matched and slightly ported inlet, cam wise i had a piper 285 in mine and it was spot on.

thats the 2nd spec 2nd i had in my xr2 and it pulled like slag from whatever revs you opened the throttle! i later went for a stg3 head with loads of porting/reshaping and +1mm valves. felt soooo shit in comparison until you got over 4k, it made up for it all then though