64 Valiant Engine Wiring Harness

Just picked up a 1964 Valiant that had a 360 installed in it. About 10 miles into the ride back from the shop, after the motor and transmission was installed, the engine caught on fire (That's what I was told). Wiring was all burned up. My question is, do I need to be looking at a replacement wiring harness for the car, which originally came with a slant 6, or for the engine, a 360 which came out of a Dart? I guess to simplify, is the wiring harness matched to the car or to the engine?