what Gus is tryin' to say is...
Bob -
Your rig is no doubt a conversion, and it looks to be a really nice one. Okay, basically there are two versions of axles - single rear wheel (SRW) and dual rear wheel (DRW) or dually. Both versions, providing no swaps or conversions (ie: Factory) have identical wheels front and back, and the suspensions/hubs for both are designed to allow for only one of those varieties, not both - Meaning you can't use dually rims on a SRW axle, and while you can mount SRW rims on a dually hub it would be both dangerous and it'd look really silly, not to mention it'd probably bash the fenders in the front.
But in your case, you have a dually rear axle (probably converted to be that way) and what appears to be the original SRW front Dana 60 axle, and as such you have 4 dually rims in the back (as it should be) and the correct SRW rims on the front Dana 60. I'm guessing you have a front Dana 60 as I doubt there would be a 3/4 ton Dana 44 under the front.
Bottom line - As your rig sits you will have to carry two spare tires - A SRW one that would fit the front, and a DRW one that would fit the back. Not a big deal but one you'd have to do nonetheless.
The alternative, is to convert the front Dana 60 SRW axle to a Front Dana 60 dually (DRW) axle, along with two rim/tire combo's. In the long haul that's what I'd do, and the dually front 60's are out there, but you'll probably need about $1500 to get one. Again, down the line that's be your best bet, but for now go out and scare little Hondas with yer rig amigo - It it one Big Bad Dodge bubba!
I built a gasser '74 crew cab a while ago - learned a lot, and I not only converted the truck to dually, but also to 4x4, and I had to get a dually front and rear axle and all the suspension. I can tell you from very personal experience, that swapping axles is very simple... just that the parts are REALLY heavy. Here's a pics of my old Power Wagon: It's a bit hard to see, but the lugnuts on the front stick out past the rim edge, hence a dually -

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Later amigo -
- S