Hi John,
now i had the same problem with my road king when we triked mine and i ended up doing a big bore up-grade ie biger pistons ,pots and cams and a stage 3 this made one big improvement to the speed etc yes i also droped in fuel comsumption but then the roadking had become a trike and i put that down to she had put a few pounds on like her owner...
now the trike does well over the ton...with regarde to your pipes ,how are these confugired ? from the picture it looks like you are running to down pipes into a twin rear barrel silencer ? (opps sorry john you do say )you may do better running 2 down pipes into one that will give you a better air flow out etc and i find a better power set up , also it sounds like you only have a stage 1 set up ? with the fueler and air filter think of a stage 2 or 3 much better, it never ends John making the HD better the above does sure cost a bit but it gives back the performance to the trike that i think is lost in the conversion, you may just wish to change the cams that makes a big difference..
what ever you do i wish you luck buddy.....
RB