A fella i wheel with ran those in 36" flavor in the Ultimate Challenge 2 years ago. I rode in his rig down at Roushes Creek in PA last fall after my truck broke. Those tires grip very well, excellent traction in rocks and they clean well. They also have soft sidewalls for great ride and good deflection. I have ran the BFG A/T in the past with very good luck. They last forever, decent traction and are quiet on the road as compared to other off-road tires. The A/T's is what i would recommmend for a DD rig.
As far as my S-10 getting a V-8, probably not right away. The 4.3 has the same HP as a 305 and it is easy to modify for more HP. I will be keeping the rig as light as possible and i wont need alot of HP for crawling anyway. The Rockwells have 6.72 gearing so those will give me the torque i need. A 350 is an easy drop in though.