Tom:
Sorry it took a while to get back to you. I've been busy at work and out of town this weekend. Mine are mounted on the original seat track (post up). I agree they make you sit up a little higher in the seat. I'm sure I wanted to take the amount out of the seat cusion to justify the argh in the dairyaire for a 2-3 hour non-stop ride
Be careful on drilling the holes (if you haven't already drilled them) to make sure you don't turn the bottom of the seat into swiss cheese. But even when I have the hard-top on the seat difference is no that bad. The problem I have is the stuipd lever on this thing isn't long enough. But heh that would just be one more thing we would have to retro fit on these cars.
J.A.