maddawg,
My 2003 Year One catalog shows the following part numbers for the 1972 Challenger dash harnesses:
HU295E - without Rallye gauges
HU297E - with Rallye guages
I used a Year One harness on my 1970 Challenger (see "Banana Challenger Project" threads on this site). It worked fine.
Matter of fact, I got all the wiring harnesses that Year One offered, for my car.
MoparMan