How do you repair rust on van roof i have a 85 ram van above the windshield there is a 3 inch hole rusted through?

you want a professional to do that, it takes a lot of sanding, de-oxidizing and painting to accomplish that. i recommend if youuve never delt with rust on a cr, don't do it you could ruin it entirely

You don't repair a thermostat. Generally they need to be replaced. They generally don't cost very much...under $10.

Have a shop do it. Trust me. People who spend their entire life working on these vans ("Vanners") will do engine swaps on their own, do their own 4x4 upgrades, swap Dodge parts onto Fords.... but...

Depends on trim, wheelbase, etc. I have a mostly empty 1996, standard wheelbase conversion, with all but the front seats removed. Weight with half a tank of gas and me (132 pounds) is 5,069 pounds.

Yes, the powertrain options for these years are the same, and the vans are physically identical.