daddy - as I pointed out above, the roller assemblies are not an exact match on dimensions:
inner roller = bore:32.550mm/outer d.:72.260mm/outer race width:19.00mm
inner ball = bore: 31.760mm/ outer d.: 65.1256mm/ width: 19.2786mm
.... add a silly millimeter of wear anyplace and double the mismatch, which is why the parts houses and bearing suppliers can't give us a cross reference, there is no direct replacement - someone went to a lot of trouble to find the closest match they could because they wanted to sell something .... maybe if you had a good mic to check all the pieces you could use some shim stock someplace
additionally, re your big tires, a buddy of mine has wider rims and fatter radials on his 55 with the stock bearings and brakes - he's fried bearings and broken spindles because of those tires that exert stress forces the spindle design wasn't engineered for
Bill