Gold Lifetime Member
Join Date: Jan 2003
Location: Lavalette WV USA
There is a brown wire that supplies the factory tach in the gauge harness. I'll try to dig up my wiring diagram, but I have HEI and my tach worked fine when I spliced into that wire (same wire that runs the fuel gauge on a non-tach car). Now, however, I have a new wiring harness from M&H Electrical Fabricators that is custom modified for HEI.
1967 RS Coupe (clone): 406 SBC, Thorley headers, Muncie, Hotchkis suspension, Centerline Matrix 17" wheels with Nitto 555's, Baer brakes, 12 bolt 3.73 posi, RS conversion, Vintage Air, PPG Hot Red. (SOLD)
1968 RS Coupe: Project...Mini-tubbed, Cammed LS 6.0, T56, 12 bolt 3.73 posi, Ridetech 4 link...slowly adding more...