Can I use a 74 dash harness with a 70 engine harness? Not worried about originality on this car...it's just a driver 6cyl 70 Challenger I made into a big block clone. I have a perfect 74 rallye dash setup that I'm gonna throw in the car but I'm not sure how the engine and dash harnesses will jive together. Any info will help...thanks!

Just a Followup....I installed the dash harness and it won't work with the 70 light/engine harness. It all connects together fine but IGN 1 ends up cranking the car over and when it's bypassed something was stealing voltage from the ignition system. The car had a terrible misfire. Ended up re using the 70 standard gauge harness and everything is fine. The IGN. 2 circuit is tied into the seatbelt interlock and with no diagrams that I could find, trying to make it work together wasn't worth the time and effort on this particular car.