top speed for a Tucker
hell i would not want to run one over 20 mph for very long, they are noisy beasts. 8-12 mph is the sweet spot on the one i use,although on a steep down hill at 6,000 rpm in 5th gear it will hit 32 mph ,feels and sounds like your riding in a blender
not recomended.
If you can get your engine up to 6,000 RPM then it's likely the King-Seeley velocity governor under the carburetor is broken or missing.
Tucker installs that governor because of a hydraulic pump limitation. The pump is typically a Vickers V-20P and Vickers recommends a maximum pump RPM of between 3,400 RPM and 2,400 RPM depending on the pump's output volume. Tucker sizes the pump based upon options such as steering only, or adding higher output if you have a front blade and/or rear hydraulics.
They install that pump on gasoline engines as an engine accessory and power it with two V-belts driven off a pulley on the crankshaft. If you measure the pulley diameters and do the math You'll see they are trying to slow the pump down relative to engine speed (larger diameter pulley on the pump).
(This is purely from memory so the dimensions may be off.) On my Tucker the pulley on the hydraulic pump is eight inches in diameter whereas the crankshaft pulley is six inches in diameter. 2,500 pump RPM equals 3,333 engine RPM. At 6,000 engine RPM (assuming the same geometry) that hydraulic pump is turning 4,500 RPM.
As far as Tuckers and "quietness of operation" there is a modification Tucker did in the mid to late 1980's to the carriers. Previously they used a steel framework with replaceable hyfax on top that supported the track on both sides of the drive sprockets. However this modification removed that framework and replaced it with damper wheels. 1300 and 1500 series machines have one damper wheel on either side. 1600 series machines have two damper wheels on the long side of the carrier and one on the short side. It makes for quieter operation as the sound of the grousers slapping the hyfax is gone. Some older machines have had this modification done to the carriers. However the cost of the parts to do it is expensive.
Tucker offered different automatic transmissions. Early on options were a Chrysler Torqueflite (a heavier duty version of the Loadflite) or an Allison AT-545. They had problems with the Torqueflites and then just went with the Allisons. I should probably point out that the Torqueflites came with either a short tailstock or a long tailstock. In the Tucker application they used the short version. From my understanding those are prone to breaking and they are virtually impossible to find.
They also offered different Diesel engine options such as a Detroit 4-53 (I'm not sure if that was offered in a normally aspirated version), a Cummins V-378 (turbocharged and normally aspirated), and a Perkins option as well.
The front blades on the Tuckers in the late seventies/early 1980's actually attached to the front axle. There was a fairly robust framework behind the axle to transfer the load from the axle to the Tucker's main frame. What's "weird" is that typically in a vehicle the blade attaches to the vehicle's frame. When you turn, the blade stays aligned with the vehicle. With these Tuckers when you turn, the whole front axle turns and if you have a blade, that turns with the front axle.
I don't know when Tucker started offering locking differentials from the factory. In conversations with Jeff Godard at Tucker they prefer the Eaton e-locker to the ARB. However Eaton doesn't offer an e-locker for the Dana 70 series axles yet so that's why they use ARB's in that application.
I would recommend you call Tucker and chat with Jeff Godard or Dan Dressler. Very knowledgeable, very nice guys who are generous with their time.
your snow conditions may be different than mine and track size and width along with total PSI , gearing , horse power can all be factored in. i saw a turbo v6 Spryte once that could hit 45mph and roster tails of the line
