Here is a pretty good map of the Bradford Ridge Path:
http://www.mapmyhike.com/hike/united-states/ca/-lake-arrowhead-area/144125121800846786
Note you can change the "Map Type" from Terrain Map to Satellite Map, zoom in and you can see the trail. Click the "Elevation" box in the upper right and it will show the grade. Note the 15 to 19% grade at mile 1.5 to 2.5. That's the tough part coming out. Using Google Earth you can see the trail and get GPS coordinates along the way.
If you don't want to camp by Highway 173, I would recommend somewhere in the middle 1/3rd of the trail; before and after is steep and/or hilly. North and west of the trailhead on 173 is very narrow in places but not too bad with 4X4. It can be very tough right after a storm (until it gets worn in). I have only been to the south on 173 once, so others have much more experience here than me.