It looks like this was the late Jack Sliker's Mustang Race# 17 which was also raced as the Kenworth Special at Reno in 1978 or 1979. It was still owned by his widow at that time. This picture was probably taken around 1970 when he had the Cessna 310 tip tanks installed for cross country racing and for racing in the California 1000 at Mojave. I think this aircraft was the one that Wiley Sanders purchased in the mid 80's which raced as Georgia Mae with either John Putman or Ron Hevle as the pilot. However, I don't remember the final outcome of this aircraft following an accident at Reno during a cross-wind landing in 1985.
T J Johansen
Agree with William Yoak on this one. The tip tanks give it away. You can see parts of the race number on the fuselage, as well as the red fuselage stripe. This is the plane that later went to Harry Barr if I'm correct. N10607 is/was the registation. T J Johansen