C30 heavy duty rear axle top speed

[burnin oil]

Jocko. The CH465 doesn't have a tailshaft. It has a really large plate on the rear which acts as a bearing retainer and seal holder for the yoke. Remove the yoke and bolt if off. The GV would then bolt up like a transfer case.

In honesty the GV would be the easiest install but like I said they are pricey, around 3 grand. You wouldn't have to pull the trans to install but the driveshaft will need to be cut down.

If you have a pull a part near by you should be able to pull a NV4500 pretty reasonably and be all in with a new clutch for under a grand but then would need a pto. Swapping rears is just the cheapest and easiest way to get there. Unfortunately you will be going 8 lug. I bet that the front dually adapters could be swapped for the 8 lug setup. Now the issue is you want to keep your rims and tires.

Best bet for you is an auxiliary transmission. I think I paid 200 bucks for mine years ago. Check them out on YouTube. A 3spd aux would give you 12 forward gears and approximately a .75 od. If you don't want to shift them you don't have to. Stick it in Od and drive like normal. Some old timers called these brownie boxs. This option would bolt up just like a divorced transfer case so you would need to cut the rear shaft and get a jack shaft to go between the aux and 4spd transmission.