I would like to replace the input pulley on my '68 Charger with one a little smaller. Are there any other sizes of WH pulley?

Not sure what you expect to gain on an auto other than maybe heat? Granted, I'm a stick shift guy all the way.............

I've increased the hp to about 20 and I would like a little faster road speed. The 8 speed I had was faster than the hydros. I'm looking for 1/2- 1" smaller.

They will make the tractor go faster for a little while.
But -- Due to the location of the hydro pump (mounted on top of a heavy cast iron transaxle case) there is only one direction for the parts to fly when they "come un-glued", and that is straight up.
Drawing an imaginary line from the hydro unit straight up would mean that the shrapnel would inevitably find it's way in to the operators "hind quarters". I'd say that's convincing enough for me to not want to alter the pump speed on a hydro.
Why not crank the engine up to 4000 rpm, and see what happens?
The hydro should have the same (or more) ground speed as a gear transmission, providing the tire sizes are equal. Maybe there's an issue with the pump or motor.

Don't alter the pump speed, but increase the rpm? How much of an increase in pump speed are we talking about? My original question was, did WH make any other pulleys? If so what did these pulleys come from. Understand I'm talking about pulleys with the fan spokes.
I could change the front pulley, but that involves sheet metal work.

You want the pump to turn faster for more ground speed, and you will do it. (we can't stop you)
In order to "de-assify" my post, I merely suggest speeding the engine up to see if you will acheive the ground speed you desire.
(It's a -*test*-('") that won't create any extra work, or require the removal of stubborn pullies, and perhaps very little use of a wrench - period.)

The OEM front pulley on the hydro tractors is already the largest offered at 5 ¼". You'd have to get one custom made with the PTO clutch disc mounting holes if you want to go larger.

I'm thinking the input pulley on the early hydros is smaller, but it also requires the bolt-on fan. P/N is 6109 (NLA) and it can be found on 875/1075/876/1076/1276, etc. models.
Perhaps someone on here can measure one?

Electro12,

I'm gonna add my two cents here as well...

Every Sundstrand I've ever seen is faster than an 8 speed, all things being equal, UNLESS it is worn out. Speeding the pump up may destroy it much faster than one that is in good shape...

To add to Terry's caution, if it's already limping, well, you get the idea...

At any rate, good luck!

Kevin

Okay! I don't want to be mule-headed about this. It's not that important. Thanks for your help!