I put this on my Issimo FM470 3 speed (same as the Fantic Issimo w/V1). it has a tight fit with the adjustment screw on the top of the carb but with swapping out some parts it looks like it will fit on a standard V1.
*the SHA did not work with the square head from the Non fan cooled motors. Worked fine with rectangular hi-comp heads and should be fine with stock oval style.