Any clutch fan options for 73 dart, /6?

The OP's car is a '73 with much more fan-to-rad clearance than a '64.
Well, it only took 1 year & 1 month, but hey.....who's counting!!! As delivered by Ma' Mopar, there isn't a whole lot more room because of the core to mounting offset.
The difference between My '64 GT's @ 2&7/16"('vert) and 2&9/16"(Cpe.) is well within the assembly tolerance at 1/8". My '72 Factory A/C /6 Duster is @ 2&15/16"...
these are from the pump pulley mounting face to the back of the rad cores. So the early A is giving up maybe 1/2" total to a later A even though the later A has the eng.
set back from the frt. axle well over 1" more than the early A. The main reason for this is the later A rad frame offsets the cores rearward ~7/8" more. I started to think
back as to how I managed to get that clutch in there when it hit Me, I had loosened ALL of the eng./trans mount bolts and pulled the unit back with a come-along, once
the clearances in all the mounting holes was taken-up I cranked 'em down. It was enough & I never-ever had a single issue with contact, it was a very tight job to R&R
the fan & clutch, but it was doable.