straight axle 44 the front. there's nothing wrong with them. you're biggest problem will be weight and cog anyway. that's a heavy truck with a short wheelbase. You should have a 9" rear, plenty strong with a few upgrades. You can build a great rig for a minimal investment with the platform you have. Probably has the AOD tranny, if not it's a c6. Either are good transmissions. I'd guess probably a 1345 or 208 tcase. I'd replace it with a 1356, just my opinion. Custom radius arms with a trac bar like the 77.5-79 Broncos/F150s would be fine too. Don't overthink the whole thing at first, you'll get overwhelmed. Build what you can as you can afford to.