Hank,
You would probably be better off tilting your hitch head back a bit and using the 5 links under tension as you originally did. Using only 4 runs the risk of jamming the wd bars into the brackets and sliding them back or forward on the A frame. 5 links is usually the minimum recommended by most manufacturers to allow room for the bars to go back and forth during turns. By tilting the hitch head rearwards some more, you can get additional lift on the bars with the same amount of chain lengths.
If you have not already seen it, we have an old but excellent thread on how to set up the WD hitch stuck at the top of this forum
here. Part of it discusses the reason that manufacturers recommend a minimum of 5 links under tension.
Barney