A833 OD 340 4x4?

well at 1500 ft then;
my recommendation would be a minimum 360.
But again, you will have to build it for the lowest operating elevation, else, at the lower elevation, at WOT, it could detonate itself to death.
In lieu of EFI;
I would recommend a Double-Pumper for ease of jet changes.
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I'm at 930ft exclusively,and 3650 pounds, and I run a 360, so I know that it is possible to make a 360 into a "powerhouse", and with gearing, to make a "torque-monster", and with the right combination of parts, mine has made better fuel-economy than any 318car I have ever had. The 360, IMO, is an extremely versatile platform.
But it cannot do all things best; generally pick two; you can make torque and economy, or torque and power, but forget highpower and economy.

And finally; if the factory iron open-chamber heads have to be used, that puts a bit of a limitation on what you can do, at 1500feet elevation, depending on your expectations..
What I mean is your total chamber volume before any machining, with those iron heads and KB107s, is about 88cc, making your Scr at .020 overbore to be
(744.6 +88)/88=9.46
So to get the pressure up to 160@1500ft elevation (about the max you can run on pumpgas) will require a cam with an ICA no greater than 53* ................ about what the 360 2bbl has on it.
As soon as you start closing the intake later, it starts dropping the pressure, and away goes the bottom-end torque. By an Ica of 64* like is on the 340 cam, the pressure is down to 145psi@1500ft.
Now; you can overcome this, to a degree, in low-range for off-roading. And in high range, you can get off the line with a high-stall TC.
But;
once you get to second gear in hi-range and past the stall-rpm; that's when the lack of pressure shows up, which is only made worse by a heavier vehicle.
But once you get up to where the power is, it's not so bad anymore. But getting there with hiway gears can take a really long time. And if, in addition, you have a performance cam in it, then the powerband will be even more focused on top-end power.

Here's my opinion on the A833od for this application. What happens if you spend a truckload of money making it work, and then you drive fifty miles and break that fragile 20tooth mainshaft gear? Which then takes out the cluster drive beside it? And now, not only are you walking, but also shopping for another Box.
IMO
a far better and more reliable idea is to use the 727.
I had a 92 Dakota 4x4 dual-range. With a column-shifted 727 and a floor stick. That worked really nice. Had that been an off-road truck, I would have installed a floor-shift for the auto, and had a blast. But for me it was just a winter utility truck.
Hyup, IIRC that was a 4-speed auto with a lock-up.
IMO, that would be ideal.