Look at the full size Dodge vans (with the later style cable setup) pedal assy. Bolts to the firewall with two bolts very easy to mount and work with. There is a rubber bushing retained with a simple clip on th interior side that supports and locates the cable in the firewall. Pretty clean and simple setup.

I think they can be found on about 86-87 and up with the fuel injection. I just pulled one from a 90 last week for one of my projects