toploader gear questions

i posted awhile back regarding my toploader for my 66 fairlane and i thought that maybe i can swap just the gearset reasonably? what would it take to do that? currently it's an HEH-BV 4 speed, but someone changed the gearset to the 2.32 close ratio and i need to change it back to the wide ratio so it'll work on the stock 3:25's that i've already rebuilt and installed. what parts will it take to do it, and how hard is it to do? thanks in advance. regards!