Dave just use the next hole in on the bellcrank. Just be sure and do the same on the other side. This will give you a little less throw. If that is a problem just go in one hole on the other side of the bellcrank where the clevis is also.
NOT A GOOD IDEA
This will make the slop worse. Go out on the bellcrank and out on the aileron horn if at all possible.
Dave single servo aileron setups using bellcranks are notorious for slop. I will repeat my warning about flutter but if the slop is 1/8th at the T.E. and the ailerons feel solid after the slop is taken up AND YOU INTEND TO FLY AT SCALE SPEEDS AVOIDING FULL POWER DIVES then I would give it a go at a deserted air strip well away from people. But if you hear a buzz in the air slow down and land as quickly as possible.
To see what happens if ailerons flutter watch this.
http://www.voy-tech.net/friendsrides...afalecrash.wmv