2 very popular modifications amongst the Foxbody crowd is to perform a 4-lug to 5-lug conversion and to swap the rear drums to disc brakes. Perhaps the best part about either of these mods
is they both can be done in their entirety by sourcing parts from other Ford vehicles (aka, a BUDGET friendly mod!).
FiveOhInfo has compiled a comprehensive guide (FAQ style) to help those out looking to perform either of the conversions, listing what parts will work, where to source them and even a (very) basic estimate at cost.
For more info, check out the article.
Foxbody 5-lug and disc brake conversion FAQ.
The guide doesn't only talk about swapping the rear end, either. It goes through how to upgrade the stock front brake system as well.