Axle help

[superbee70]

Thinking of swapping axles in my truck. Looked at an '89 dodge 3/4 ton today. I'm guessng back is a 60 and front is 44 but not sure. Have the vin but not sure that will say. It's a small block auto trans. My question is it looks like the front axle has a vacuumm disconnect. Would dodge have them in this year? Whats funny is the axle has manual hubs? I thought you had one or the other? Or would this be something someone added?

If it is a disconnect would i still want it? Not looking to do anything crazy with the truck, mainly looking for gearing and brakes and better choice of tire.

Also it looked like a throttle body injected engine. Couldnt see a vac can on distributor either. Guessing it's computer controlled. How easy is it to keep fuel injection? Would definjtely switch to a manual. Would that be a new comp also? Or swap to carb and new dist? My old m had a 318 carbed i swapped in and ran well but that was years ago.

[RMS]

I wouldn't run a 44 on a 6000lb 3/4ton(off highway) m37. jeep guys say if your running anything over a 35in tire that one should get alloy axles or carry spares.