I was fortunate to score a Rostra kit from a flea market for $15!
http://www.rostra.com/
This system has the LCD integrated inside a newly provided rear view mirror. Works real nice. The instructions provided were for a Toyota truck but the Trac was very similar.
I mounted the camera on the tail gate just to the left side of the latch. Sheet metal re-enforcement in the gate prevented a center mounting point. But the fish eye effect is so extreme you can't tell the difference. The video wire comes through the rear tail lens rubber plug. It is then tape wrapped around the existing stay wires on the left side of the gate.
Hardest part was routing the wires through the headliner and down the rear driver's side pillar. Saturday afternoon job. Used heavy wire to pull the wires through. I should have taken pictures and posted a project!
The rear view mirror mount was for the Toyota, but it slipped right onto the sport trac dove tail mounted on the glass.
Highly recommended if you have a rear cap on the Trac as I do, which, BTW, is a used Lear cap that I paid $100 for off of CraigsList. I sure know how to score the deals eh?
I feel so much safer with the camera. Took a little while to get used to it, but now seems very natural.