The 10.5 is virtually the same as the earlier 10.25 model with the exception of a .25 inch larger ring gear diameter and the pinion bearings. The 10.25 gears can be used if used with 10.25 pinion bearings on a sterling 10.5 rear end.
In my case it's cheeper for me to regear then to buy more new tires. I have to tow alot more now and lugging my motor and trashing a 4500 doller trans. is now what I need now so regearing is the best op for now.