Stop in for a cup of coffee

You would be much better off using a good original, used, OEM harness, they are out there.... The connections with what you have will be the issues...IMO
yeah, ive got a good, 64 engine harness coming. its been finding a good chassis harness that isn't messed with for a 64 thats been my biggest problem. The problem is, mine is a 440 trim package and a 4 door, the wiring harness is different between the 4 door and 2 door according to the 64 wiring manual i ordered off ebay.