Probably not, but....
The first thing I'd do is check and make sure your outhaul is long enough to reach the clew of the new mainsail. Otherwise you may have to re-rig the line in the boom, which may not be so simple. I don't know anything about the setup on your boat, so I really can't say. As far as affecting sail trim, my guess is that the reduced sail area will mean a bit less power. I doubt it will act like a reefed sail because you didn't mention the luff being different, so I'm guessing the head of the sail will still go all the way to the top of the mast. Although the mainsail is reefed by removing sail area along the foot, the result is removal of sail area from the top of the mast and lowering of the CE. If the CE obeys the rules of basic trigonometry (and that's a big "if") a shorter foot will move the CE forward, but won't lower it. I also doubt that the shorter foot will move the CE forward that much, and even if it did, I don't think the new location of the CE will affect boat balance significantly. There are many other things that affect boat balance much more that CE location. Two of these are basic sail trim and the amount of heel. Of course, that's just my opinion...I could be wrong. Happy sailing. Peter H23 "Raven"
