I've been doing some research about the original Kong figure:
Height: 40"
-Head 10" tall
-660 pounds of fur
Pictures from Air N' Art Designs:
I don't know how similar the USF and USH figures were, but according to an LA Times article regarding USH's tour figure:
-Weight: 7 tons
-Powered by Compressed Air
-4 large pumps, 12 small pumps (7 ones specifically for his plastic lips)
-Air Bags were used over the rigid frames to create the illusion of his mass
Finally, I found some interesting facts about the Ride Vehicles:
-Designed by Intamin
-Hung by cables at each of the four corners
-Arrow Developement created accordion-like bellows which sat on top of the cars