Dana, I thought they were metal back then not plastic. You say, "not necessarily", does that mean for basic motor 6cly or a HP one as the OP states it is.
What I was pointing out is not all cars got shrouds, maybe in 69 or 70 on all cars got one? My stock 67 dart with 273, 2bbl, and CAP only got a 7 blade fixed fan, no shroud.
I did not make any distinction between plastic or metal shrouds.
HD cooling, AC, Towing Packages, 383s were most likely to have had a shroud.
Thermostatic fan clutches were not commonplace till the late 60s
The OP's car IIRC started out as a slant 6.
The OP's car certainly has been hot rodded in the most truest sense. Engine swap - trans swap (I assume) who knows what else.
My guess is the person/person's hot rodding the car did so with parts available to them, so it will naturally be a mis match of parts.
Chrysler had alternators before Ford and Chevy, my 63 Econoline van had a generator, my mom's 65 mustang had an alternator. 60 Valient had alternator standard.
