I'd check to see how much taper you have in your cylinder walls. I'd also check the head for cracks. You may want to just to just grind the seats, the idea of hardened seats has mixed results and if your going to drive your truck on a limited basis I think you could get by without hardened seats. Also, did you check for clearance on rods and mains? Your truck should have had shims in it and if the bearing surfaces are not scratched or scoured you may be able to adjust clearance and polish up the crankshaft. Look a bit closer and things may not be as bad as you first thought. These old engines are tough.
