8 3/4 axle tube ends , and a dana question

where are some places i could get a couple of 8 3/4 axle tube ends?(i am working on putting this dana together) i found them on ebay for 89 bucks, but i didnt know if what other options were out there.
also this thing has a 4.56 gear... that is a lil steep!! to change the gaer ratios , can i change the carrier? or do i need to change the whole rear end?