Interesting thought, I expect it is off the beaten path enough that you just have to try it & see. Keep the carb extra-rich until you know how much torque you are getting from the FY pipe. I expect it is a wide, as in non-peaky power band, which is good for an experiment. Not as likely to melt a piston as a peaky pipe! If you have an egt gage on your HPV, it will tell a lot about how to tune for that pipe.