If its the boot that goes on the shaft that goes between the differential and hub, then yes its a CV boot, if its broken there should be some grease slung out of it.
replace it ASAP, or get a new CV axle....but the best thing to do would be to buy a LSD with new shafts and output flanges...
Discount tire has a lot of enkei's under exclusive contract I would try them first...if they cante help you I can call enkei direct and see if I can get my hands one one.-chet