Jenkins retired as a driver, hiring Larry Lombardo and Ken Dondero to drive his cars so that he could concentrate on research and development. Lombardo replaced Jenkins in the driver's seat for the second race of the 1976 season in NHRA. Lombardo won that season's NHRA Winston Pro Stock championship despite the late start. Dondero won the AHRA title. Lombardo raced for Jenkins until 1979, finishing third in 1977 points, second in 1978, and seventh in 1979. Jenkins cut down the team's match races in the early 1980s until his final season as a team owner in 1983. Joe Lepone won the 1985 Winternationals with a Jenkins Pro Stock engine. Grumpy's main focus was on Comp engines, which were used by a large client list, including national event winners Garley Daniels, Steve Johns, and Bob Kaiser. He led development of GM's new splay-valved cylinder heads for the Chevrolet small block V8 engines, utilized in the new
Pro Stock Truck category in 1998. He fitted the splay-valve heads in a engine, used by Larry Kopp to win the 1998 Winston drag championship, and by 1998 national event winners Tim Freeman, Brad Jeter, Johns, Mark Osborne, Scott Perin, and Don Smith. Jenkins-built engines continue to be used. A Jenkins powerplant was used by Dave Connolly in his title-contending Pro Stock
Cobalt to win the 2005 Winternationals and briefly placed Connolly in the POWERade points lead. In 2006, two-time Pro Stock champion Jim Yates announced a testing program with a Jenkins motor in his 2005 Pontiac GTO. Jenkins also worked on some
NASCAR engines. He built the engine
Donnie Allison used to take the
pole position in the
1975 Daytona 500.
Mike Swaim used a Jenkins motor to take the pole for the 1987
Busch Series race at Daytona. ==Halls of Fame / Awards==