How many of us are there? Owners of Dodge based RV's?

My 77 Allegro class A had a problem.The fusible link between the starter relay which is mounted on the frame on mine to the switch circuit burned out. The previous owner did a little creative wiring on his own. causing her not to start. can i use a maxifuse in it's place and how big? the link was gone and a 16 gauge wire rigged up in it's place.I also need some 17.5 tires if anyone knows where to find em! good to see there's more people out here like me,now i won't have to sneak around those new prevosts, ha!