RAM makes a rail mount that will fit your PIV rail, I drilled the mount and used a set screw to lock it down. I put a piece of rubber on the arm to be a shock absorber, it has worked fine for me on my HDS 10, I think it would work great with the less weight of an HDS 8. I had a Hbird 900 mounted the same way with no problems. Some of the guys have mounted them on the fiberglass in front of the throttle, but I couldnt find a spot that would work for me, others have made a plate over the dash hole and used a ram mount on that plate. Mike