There does not seem to be a data base for the early Grand Villa bodywork.
My guess is that the wheel wells stayed the same . My wheel wells are 41 in wide at the hub height , aired up . The RR was a little close to my new tires and it measured 40.5 in.
My data plate calls for 9 R tires and they spec out around 38.5 in . My new 295/75 tires fit but are close to the body/wheel wells.
How big are your wheel wells and what is the data plate tire? Info just for fun.MM
Data plate tires are 275/80. Rear opening is 43" at hub height. Front is 40.5" at hub height. Tires were switched to 295 in 1999 with no sign of contact since, even when the coach front got airborne on a OKC bridge ramp, really big boom and huge shudder when it hit. Not sure about the rear, but anything in the coach that wasn't secured took a ride, and the little water that was in the toilet was ejected. Pulled over to check for damage and did not observe any. Beamalarm indicated 10r tires for the 300 hp models IRC.
attached of photos with the 295
attached is photo of rear with 295
Your Fender openings are about 4 in longer than mine. I have 3/4 in gap to tire at the closest point. I lost the bet:)
275 vs 295 diameter
295/75-R22.5 vs 275/80-R22.5 Tire Comparison - Tire Size Calculator | Tacoma... (https://www.tacomaworld.com/tirecalc?tires=295-75r22.5-275-80r22.5)
We ran the bus about 300miles over the weekend. No rubs , the speedo is almost perfect and the ride is good. I lost a little acceleration going to the 39 in tall from the 37. 0 To 60 is about 27-28sec. Full tanks. Up about 2.
1/4 fuel and water tanks are good for a 2sec improvement with my 250HP.