Does anyone make replacement parts for the front axle of 63 chevy 4x4 that is 3/4 ton?like the spider gears?

My 4x4 doesn't pull itself in 4 wheel drive mode.It has a popping sound coming from the front differential.I am guessing that it is the spiders or the axle drive gear inside the differential.These parts aren't available in my area.So I am looking for new replacement parts or maybe a salvage yard that specializes in older chevy 4x4 parts.Can anyone help?|||try this sight





http://www.accuautoparts.com








or maybe this one





http://www.4wheelparts.com|||it could be you hubs LMC truck has descent selection


http://www.lmctruck.com/icatalog/cbe/full.asp?page=77