I was reading a discussion on a model car message board about the new Revell 1970 Charger kit, which has a Hemi and the Magnum 500 style road wheels. http://www.revell.com/model-kits/cars/85-4381.html#.WdZG6YprzUY
On the message board it was stated by some that the Hemi cars could only be purchased with 15" wheels and therefore the kit wheels were incorrect, but there are other sources which indicate that F70x14s were standard equipment on all R/Ts, including Hemis. I hesitate to ask this question as it only relates to a model car, but it is interesting nonetheless.
Here are the sources indicating 14" wheel availability:
Both above images from Hamtramck Historical: http://www.hamtramck-historical.com/library.shtml
Then there's this build sheet from a '70 Hemi Charger that shows it was originally equipped with 14s (it was said on that board that is is probably a "1 of 1"):
from this page: http://www.1970hemicharger.com/build_sheet_decoded.html
This is more out of interest than anything, but can anybody shed some light on the Hemi 15" wheel thing? I have only seen documentation that supports 14" wheels being standard on them.