16 year old needs help with disc brake upgrade!!!!

Your talking about the ..block..in the 8 3/4 center section.Instead of going with Yukon axels(28 inches),go with Moser axels.you,ll beable to slide them in without removing the block.Call Moser and tell them what your doing and what you want,they,ll fix you up quick.Write down your rear brake size,you,ll need this when talking with them.Good luck.