Ours adjust, but like has been mentioned once set I don't mess much with them.
The combination of the .....
....lazy-jacks and the sail-pack has been great. We love it.
The lazy-jacks....
.... part of the mod is here....
http://purplesagetradingpost.com/sumner/macgregor2/rigging-21.html
Note that at first I didn't have higher blocks above the spreaders on the mast, but then did add them. I think minus them was ok, but now there is no real downward pull on the spreaders.
We also use a topping lift, so don't use the lazy jacks to hold the boom up. They were simple to install and don't add much time to the setup time coming off the trailer. We don't use the boat for day sails off of the trailer. If we did that I wouldn't use them.
The sail-pack mod is here....
http://purplesagetradingpost.com/sumner/macgregor-canvas/canvas-9.html
.... and very much worth the effort to do if you are out any length of time.
Also the single line reefing that we did at the same time has worked great in conjunction with the lazy-jacks and sail-pack,
Sum
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