Reproduction 1986-1988 4+3 Doug Nash Overdrive Switch and Harness Assembly. Over the years of use and abuse, many 4+3 transmissions no longer function as designed. Switches and cables deterioate or are just not used. This Switch and Harness Assembly is a step in getting your Doug Nash 4+3 transmission operating to factory specificatons.
During the critical early years of Corvette Racing, the 4+3 was a leading edge advantage for Corvette winning the 1984, 1985, 1986, 1987, 1988 SCCA Showroom Stock Endurance Series Championships. RPO MM4 Production Quantities By Year: