Yes this was a Hydro the 416 H I didn't know what they called the gear drive. Guessing what you say is the 416 8 Previous owner changed the rear over to the gear drive.
He is not sure what belt he used whether it be from the original Hydro or an extra he had for his puller.
Surprises me that the belt for the Hydro is longer than the one for the gear drive. I thank you for that info Guess I'll have to go deeper tomorrow to measure it, Also I'll measure the pulley on the trans axle, I'm taking a wild guess at 4" ( The only reason I may have doubts on this being correct is I know this thing would run circles around my 782 on the road, I know it would keep up easily with my neighbors 2 wd Gator.... Just keep checking on this post. If problems arise I'll post here..I truly appreciate the reply. Thanks again !