Are you running a throttle rod, or a cable? Cables were only on 6 cylinders, while the rod linkage was used for 8's. I can't tell by the photo on your website.
If you are using a cable, here's what I'm using for my engine. I'm using a 6 cylinder throttle cable, and I grabbed a accelerator pedal from a Nova at the junkyard (there's another one there right now). I then ordered Summit's cheap chrome throttle cable/kickdown bracket, and there we go. It's easy to adjust for full throttle, and is very smooth and takes up very little room. No expensive aftermarket parts necessary.
Lead Mechanical Engineer
Art Morrison Ent. Inc.