Ok, I'll go with the 180 stat..

Changed waterpump & went to a 180 stay. Didn't help. Now temp goes up to 200. I shut it off before it goes any higher

Are these temps while in motion at highway speeds, in traffic, or standing still ?

Fan shroud ? Send pics please.

Do you have access to an IR temp gun ? We need the temps at the upper hose and also the lower hose after the engine warms up to 160-180.

Remember, the rad filler MUST BE HIGHER than the highest part of the engine where coolant circulates. If it is below, then you can get an air pocket that will drive you crazy.

What octane gas you running ?

Kbarkley,
How much total ignition timing are you running? Are you sure that your temp gauge is accurate? Just some thoughts. dgh

36 total timing, gets up there while sitting still, cools down roughly 10 degrees when moving. Temp gun shows 198 top hose 194 bottom hose. Radiator is a down flow aluminum 2core 3/4" tubes currently in car now. No electric fan. Other radiator was new also. 4core aluminum with elect. Fan. Top tank is above heads on block. . Im finding that with both radiators coolant Is not cooling enough. But for nomore engine then it is I don't see why it's getting warm

Thinking these champion radiators are not a good choice for this project. They are flowing too fast.

Fan shroud ?

Yep, steel fan 1 1/4" space between fan & radiator

May be irrelevant, but my sister has a 1976 Dodge 22ft mini MH with a 440 and 727 trans. She bought it from a friend of mine who owned it for 15 yrs. and used it to pull a 28ft enclosed trailer with a 3,000 lb race car.
It also has an overheating problem, if it's driven over 55mph it goes up to 215/220* if driven at 55 MPH it runs 180*. I talked to my friend who owned it, he said he never worried about it, it alway ran those temps. It scared my sister and she had the radiator rebuilt, flushed the block, put a new waterpump and clutch fan on it and notheing has cured the problem. It does have engine AC and a trans cooler mounted in front of the radiator.
It's now for sale for $2500.00 because she doesn't use it anymore.

Zip.

C'mon guys . . there's at least two, and probably three threads up here that deal with overheating, and they all "boil" down to a couple of things, either the water isn't in the radiator long enough or the radiator isn't big enough. A third might be not getting enough air through it in the right places.

On th' Mopar Motor Home. If it works good at 55 but heats at anything over, it's one of two of the above . . It ain't rocket science.