Here's an exploded view that may help you out:
http://www.texracing.com/ford_9_exploded_view.htm
When replacing a crush sleeve with the solid spacer, you must also use shims to make up the difference in machining for all the parts involved. Jeg's sells both the raw spacer and the "kit" with the shims included. Some places also sell a spacer machined to a certain width which you must supply. Unless you really abuse the car in terms of rear end load (lot of drag, running slicks and a torque peak most of the time...), you will probably be better off with the crush sleeve. It is a lot less complicated to install. To get really serious, the proper way to set up the spacer is to take some precision measurements of the parts, or assemble with known end play and measure the proper spacer width from there.
I'd say that if you want to use the spacer the "down home" method of getting it right is to have the spacer kit (with shims) and starting with just a few shims on top of the spacer (or maybe none), assemble and check rolling torque. Keep adding shims to reduce the rolling torque until you get it right. Remember that the bearings must be fully seated and rotated to properly get a reading. Also, pulling the outer cone on and off the shaft will be a pain. You'll have to block up the seal housing and press/dead blow the shaft out.
As far as measuring, you need to end up with measuring the "gap" that the spacer will fill, and then subtract about .001 to .002 (guess) to get you to the proper preload. I'd say a depth mic from the outer face to the inboard bearing cone with the outer bearing removed will give you one side. Then measure the depth from the outer face to the outside bearing cup shoulder and any offset between the bearing cup face and cone face. Voila! Easy as 1,2,3.....not.