I never used the Gear Vendor OD for my M35A2. I have the 53" tires which gives me 30% more speed. In 5th gear, power is pretty well maxed out, but it will drive at 60-65 mph.
When I started my project, I thought about taking my Gear Vendor out of my Ford 7.3 turbo diesel and installing it into my M35A2. The space between the transmission and the transfer case is way too short. Without moving the transfer case, the only way to install it would be after the transfer case. To do this, the Gear Vendor would need to have a disable switch added to the all-wheel drive selector to prevent a mismatched ratio while in all wheel drive. The Gear Vendor is solenoid shifted and would be easy enough to do.
The Gear Vendor is a planetary gear just like an automatic transmission. Because of this design, the gears are always meshed. When it shifts, a brake is applied to a portion of the planetary gear. The only parts that really go bad are the fluid pump and the brake. In other words, they can handle a tremendous amount of power except when shifting. The M35A2 doesn't create much power and the gear vendor should be plenty strong enough to handle it as it had no problem handling my 7.3 turbo Ford pulling massive loads. Go to their website and they rate their Gross weight to 30,000 lbs for recreational or 25,000 lbs for commercial. The M35A2 has a massive amount of gear reduction in the axles so the gear vendor will not see the torque multiplication. One could put a disable switch on the transfer case gear selector to prevent operation in low range where the torque is multiplied. It would not need to be used in the low range anyway. However, this would be a ton of work to make the gear vendor OD install not to mention the price tag.
I like the fact the 4-5 gear are close ratio. Shifting through the gears with large tires is OK until high gears. The close 4th to 5th makes it easier to transition to 5th gear with massive tires. I would prefer to have a transmission that has a gear in-between each gear. I often use the transfer case to split the gears. 5[SUP]th[/SUP] gear in low range is equivalent to 3[SUP]rd[/SUP] gear in high range. I still have a big jump when going into 4[SUP]th[/SUP] gear high range. The M35A2 doesn’t develop power until around 1500 rpm which is when the turbo spools up. If I’m shifting at 2200 rpm, then the next gear is way below 1500 rpm. I could wind out each gear beyond 2200 rpm, but that gets dangerously high. A close ratio transmission with more gears is preferred.