Green/red not really an issue with cooling. If you know the history or have done PM on your cooling system, aka, thermostat, wp, all new belts, new fan clutch, radiator in good shape with form seals around the core support and shroud. You should be fine. Go wheeling with a few rigs and see if...
+1 ^^^^^
Cooling is #1 and we have all been there getting stranded with an overheated rig on the side of the road. What seems like a totally normal functional rig with zero overheating issues for a daily/highway driver might surprise you when it is out on the trail. Your system will be tested...
you need to figure out what you want from your 80s, If do i all, DD/weekend trail rig, then 35s and a mild 2" - 3" lift is ideal, will need to regear, but can wait, plus possibility to upgrade to 37s in the future.