When I ordered the quadrant kit from Steve, he hadn't offered the adjustable firewall part yet. I called him a year later and asked if I could upgrade, he said no problem send him a little $$ and send the non-adjustable bracket back to Texas.
My 67 has a 351c with a t5z. I have the mustang Steve kit. I recently changed to a 96-04 mustang cable and it has been great. His old kit used a shorter fox body cable which always melted on my hooker headers but his new kit has the longer cable for better routing. I also wrapped the cable to further protect it.
It's not bad to get it apart, ditto on the Mustang Steve kit...used it on my Cougar for 7 years or so, and on other cars as well. Simple and effective. If you ever break or melt a cable for some strange reason then your local parts store should have them. I'm even using his kit on a Ford Cortina (which took some doing but it works)..