i ponderd the 19.5 thing for a long time.the problem i came up with is you have piloted hubs.meaning your rims have coined lug nut holes,one coined inward the next coined outward to lock them together.i added some pictures of my tire job today.maybe that will help.send me a pic of your rig,it might be different.i don,t know how urgent you need tires,but they do pop up on ebay quite alot.i got mine for 600.00 mounted balanced with the rims.i know that was very lucky but i would keep an eye onthe ebay site.you can also try 215/75r/17.5.instead of the old 8-17.5.   BTW iam from PRESQUE ISLE northern maine,but spent alot of time on the coast.one thing i like about these old chapions is they have solid steel wall studs and spray foam insulation,so if you can keep em runnin they don;t fall apart like the wood frame ones.good luck,i;d like to see some pics.and i could probabely decode your vin# if you haven,t already.if you have a -3 engine you have to be careful what parts you buy for it becuase they are different than your standard 360 or 440 etc.even sparck plugs in some cases.

hello Gary                                                                                                i was able to find the tires on ebay while i was working in North Dakota.I am from maine and couldn,t find anywhere to purchase them new.It's kinda funny because i just put them on yesterday and got your comment today.i was lucky to find them.took me about a year of looking.i really like this old champion motorhome,not many of us left.also there is a complete service manual on this site.