Thanks for all the suggestions!! I was running it last night and can see now that no additive is gonna help the radiator. I was recommended some stuff called "Max 13" (well, that was the old name. Not sure what the new name is. Its from Napa.) Its to get the rust and scale out. I tried it but ended up taking the radiator into a place thats going to re-core it. Not as expensive as a new radiator but the price is still up there.
At least once I have it, hopefully the truck will run nice and cool. It has new hoses, new thermostat, and it will get a new radiator.
If I'm missing anything, lemme know!
Thanks everyone!!
