OK....so a bit of information for this post.
Wayne Gapp started was racing from the late 1950's and started working for Ford in the early 1960's. Lincoln-Mercury provided George Delorean's old Comet to him which he ran with the 'Hi-Risers', a group of Ford Engineers.
Here's a link to information about the vehicle:
Wayne Gapp’s Wheelie Maker | Gapp Online
The next vehicle was a Cougar called the SuperCat. Both the Comet and the SuperCat were 427 Cammers.
See a pic of the SuperCat here:
Super Cat Cougar… | Gapp Online
From that vehicle he got a chassis from Logge, put a Mustang body on it and and inserted a injected gas Boss 429 into it and ran the AHRA East Coast circuit. This vehicle was prepped with Bill Jameson whose name can be seen on later Pro Stock vehicles as well.
See here:
Boss Hoss to Boss Gasser | Gapp Online
Since he was in charge of the Boss 429 program for NHRA and NASCAR he also had a garage business build engines for races. Why? Not many people built Ford engines those days. The biz was successful so he moved from the garage to a building. The business was called 'Performance Engineering'.
Around late '69 or so Ford decided this was a conflict of interest. A friend recommended a guy to partner with who could run the engine business. That person was Jack Roush.
Ford soon shut down racing operations and so the two went racing themselves.
The list of vehicles that ran under the Gapp & Roush banner include:
1. Super Stock - Mustang
2. Pro Stock - Maverick (2 or 3) - Boss 429 power
3. Pro Stock - Pinto(s) - variety of years *
4. Pro Stock - Mustang II *
4. Pro Stock - 4-Door Maverick *
* There are other vehicles but these are the basics
* Engine displacement depended on application (i.e. NHRA vs. Match racing) and the displacement in NHRA depended on weight factors.
Another good article about WG can be seen here:
Competition Plus
The first vehicle was fielded in 1970 and the last in 1978. WG drove until near the end where Dondero was hired to drive (1977?). JR wrenched. JR drove a few times.
I can't talk about JR's involvement in racing before 1970 though there are references to 'The Fastbacks'. I have not been able to find a single reference, magazine article or other information about the 'The Fastbacks'. If you know of any I would love to see it.
His involvement in auto racing after 1978 is well documented :-)