Properly tuned, the uppers will always have more tension than the lowers, as they need to carry more load. Uppers will often be one wire size up from lowers.
Sounds like your uppers are too loose, tighten them a turn at a time, on alternate tacks, until the mast stays in column. While there will always be "some" leeward slack in rigging, if the stays are loose enough to flop about, then adjust uppers/lowers together until the rig shows just a "little" leeward slack.
I see little value for a guage for the annual tuning of a cruising rig, if the rigging isn't keeping the mast incolumn, you tighten the stays until they do. A gauge is an important tool for racers who tune the rig to match specific conditions, where a gauge lets that change be done dockside.
Certified...in several regards...
Last edited by sailingfool; 04-23-2009 at 05:02 PM.