So in follow up to yesterdays post, I had to get under the chassis and find the square nut and put a vice grip on it. The bolt was extremely difficult to remove and my wife could not do it so I had to go up top and with great effort finally remove the bolt. After removing the doghouse I determined the following: 1: the bolts in question are 3 inch 5/16x18 Phillip's head bolts are 1 3/4 inches too long. They go into cage nuts that are attached to a slot in the coach frame. The bolts Thor used must have been defective as they twisted the cage nuts out of their slots. Die Co., Inc. | Cage Nuts
Cage nuts are not easy to find and must be special ordered at Lowes. Fortunately I still had one of them and was able to refit it into the passenger side slot. I was able to use a 5/16 x 18 U-nut that I found at Lowes to replace the lost cage nut on the drivers side. The purpose of all these efforts was to sound insulate the underside of the dog house with 3/4 inch Fatmat which I did. This resulted in a significant decrease in the engine noise in the cockpit. One more point. The screws used to attach the doghouse to the vertical firewall are also 3/4 inch too long and are self tapping Philips heads which were easily stripped I replaced the with a similar size hex head 3/4 inch self tapping screws which worked well.
I am a new owner and understand that Thor is not Ford, but I don't understand using longer screws than needed or screws that are of such poor quality that they are easily stripped.