I can't speak to whether or not 295s will fit in the fenders.
I wouldn't recommend putting 295/anything/18s on a 9" rim. The side wall is very short and the tire would not seat right. Stick with the Mfgs recommendations.
295/275 not much difference, a little less than an inch of section width. Some tire Mfgs just make the grooves wider and thus no real gain in the contact patch. Do your homework. Check out
TireRack.com they stock the major brands, have tons of info, specs, and owner feed back.
As for rims; there are places that will modify rims and will widen them to whatever size you want. Mega $$$$$.
I hope this helps.
