Your radiator has more that enough capacity to cool your MH under the worst conditions. Ford didn't cheat in that area. I'm running a 460/528 stroker with OEM radiator core, in my 95 Bounder and don't have a cooling problem. You probably don't have a radiator problem. But if you do decide to change it, beware of the copper replacement radiators offered on the internet. They don't cool properly. The replacements only have 15 fins per inch, where as your OEM radiator has 20 fins per inch. That's 25% difference in surface area. There are aluminum replacements that look like they should cool properly.
Your radiator comes out the front. Remove the AC condenser, unbolt the tranny cooler, move the PS reservoir to the side. Two screws in the top hold the radiator and condenser in place. From inside, remove two screws in the top of the fan shroud (hard to see). Remove upper radiator hose from the thermostat housing and leave it attached to radiator. It a bear's a$$ to remove it from the radiator while in the MH. Remove lower radiator hose, tranny cooling lines and ΒΌ" coolent hose, from left end tank. Pull that rascal out the front.
Richard