Charles
Here is some good info on your question, I cut a pasted the shock mounting info from Alden's site. This is how I set up my cars.
Hope this helps.
http://aldanamerican.com/suspension-installation-guides/The more vertical the shock, the firmer the ride; the less vertical, the softer the ride (but less support, especially on cornering). We recommend a mounting angle of 30 degrees from true vertical at ride height. Generally speaking, the weight of the car will collapse the shock 1-1/4 to 1-1/2 inches at ride height. Using this rule of thumb, you will achieve a 30 degree angle at ride height if the shock is mounted at 26 to 27 degrees when it is fully extended (Figure C). When designing your suspension mounting points, extend the shock to 2/3 at ride height; i.e., if stroke is 3 inches, set the car up so that at ride height, the shock as room for 2 inches compression and 1 inch rebound. Do not design your suspension with the shock fully extended and the car at rest–allow it to sag, otherwise damage from excessive rebound force may occur.