Darin your missing the point if your post was directed towards me... If the front do most of the work why would you not spend the money on upgrading those first? Any speed shop will tell you to upgrade the front brakes first before you spend the money on upgrading the rears over doing the front brakes.
Caymen I see your point now on the maintenance issues.
Seattle: My post was directed to Caymen. My point is the rears do so little in braking performance that the change from rear drums to rear discs would make little or no difference. And the lack of a parking brake would be a big concern for me.
No belittling the job... I know it's something I couldn't tackle. If I did have the tools/skills I probably would figure the benefits vs the effort ain't worth it.
Now be sure to write up a project with lots of photo's. I know there are a lot of people who will want to do this, now that someone has broken the ice
I'm sure you will be happy with them. I know when I first drove my 2003 Sport Trac, I immediately noticed the improvement in braking over my old 2001 Sport Trac.