Need some more help
 

How much tension should I have on the spring of a prong rest and how high off the shelf should it be set?

RE: Need some more help
 

Its hard to say with out seeing the bow to determin what the tension of the rest should be.

Set your rest so your arrow is of the same height of where you bolt your rest on (the threading where your rest bolt goes). So looking at it from the side view your arrow should be on the same plane as your rest bolt.

RE: Need some more help
 

A good starting point is to adjust the tension to where you can load an arrow on the rest, then press the prongs down as far as they will go. Release the prongs and see what happens. The spring has to be tight enough to lift the arrow all the way up, but not so stiff that the arrow bounces up off the prongs.

Some guys leave the tension light enough so that the arrow droops down a bit at brace height, but tight enough that the prongs lift the arrow into position at full draw.

I prefer the first method.