My 1970 Challenger with I believe 1971 rallye gauges dash has been running fine, but lately engine had trouble with higher rpms. Now it wouldn't restart after getting gas, It will start and run until I release the key from the start position to the run position and dies. I replaced the ignition switch, didn't solve the problem. I remember before replacing the ignition switch the coil showed low voltage to it. I'm running a stock electronic distributor. Does 1971 dash have a seat belt interlock system? I'm at a loss, any suggestions?