[1968_K20_4x4]

Ok excellent, thanks for the info I will keep my eye out for a big hub axle. I know that my gear ratio is 4.57. That axle that I found for sale looks like it is the small hub, so I will keep looking. My truck has a brake booster and a master cylinder that was installed by the PO so I dont know very much about it but I dont think its original to the truck. I am assuming it may be out of a later model square body truck but Im really not sure. Ive attatched some pics of what I have, maybe someone can help identify these parts?