Not really. "H" stood for Heavy Duty supposedly. As far as the 15x6" H-wheels, there were 4 different sized H's that I've seen. The A-12 cars & Hemi cars got the big H - 3 nubs, & flat bolt holes. Big-H wheels in the correct A-12 style were produced from 1968-1972. See this image.

https://www.classicchambered.com/rims/15-6H.jpg

No Man With A Good Car Needs To Be Justified