overheating 1993 Wannabago brave 27

If the previous suggestion don't work,I would use a good chemical flush first drain it, remove the thermostat and reinstall the housing, disconnect the bottom hose and clamp a garden hose inside and let it run full force. You can watch what comes out and see how fast it is draining. While the thermostat is out put it in water and bring it up to a boil, it should open just before boiling about a 1/4 in. If it still runs hot use an IR gun and shoot the temp sensor in the left head and thermostat housing and compare that to your gage reading, these gages can be off. You can then shoot the radiator with the IR gun in a 4 in grid pattern from top to bottom and look for colder spots which would indicate a blocked section of the radiator. From top to bottom you should see a change in temperature of 50 degrees. Having said all that a gage reading of 212 on a flat is not all that hot for a 454, does it recover quickly once you crest the hill or does it stay hot for a while?

1993 with mud coming out? Yes do the flush to clean the block and heads, rinse well then install new radiator.

There could be debris build up between the A/C condenser and the radiator.

It sounds to me like the radiator needs to be cleaned out better. Don't forget to check the simple things like a radiator cap.

I had that problem in a 1977 Pace Arrow, dodge M400 chassis, 440 engine.
After I did everything else, i decided that I had to remove the radiator, take it to a shop, have it professionally cleaned, and put it back.
when I moved the A/C condenser out of the way, I discovered that the radiator core looked like a mud fence! The only possible air flow through the radiator was around the edges, the center was plugged solid with dirt and bug guts! the shop cleaned it, pressure checked it and flow checked it, and I had no further overheating problems!
I would have saved a lot of money had I check the radiator fins FIRST!

As well as burping, make sure a hose is not collapsing causing a flow restriction. Also, are you sure your temp gauge is accurate?

either back flush it or take it out and have it cleaned at a radiator shop.

I did take out the air bubbles, I did get the proper funnel it's a must for sure.
I hope it doesn't come to it but I will replace that rad in a minute if that's what it needs the last thing I want to do is break down away from home.

thanks for the replies guys.

that much grud in the radiator,, I,d have it professfinaly cleaned, OR replace it.

Try 'burping' it... Most likely your "issue" is a water bubble in the radiator....Dennis

Get yourself a Lisle 24680 funnel kit. About $30 at your local auto parts store. You'll save yourself lots of headaches. You'll thank me later.....D