thats what i did with mine anyways, as my RS box mainshaft was worn beyond belief

so ran home, grabbed the decent spare boggo box i had, had that stripped and inspected, robbed it of its fullg earset and bolted it all into the rs casing with the LSD and a new bearing set

basically my rebuild cost me 200quid all in, with paying him to strip 2 boxes. but it was cheaper than buying another rs box, still with the risk that it might be a dud, and then just having piles and piles of worn rs gearsets

the gear ratio issue wasnt of any concern to me though, nor is my spec as big as yours