Alfredo, I am in the same situation. I was fitted for the t100s irons with modus3 105 regulars. 7 iron at 80 mph, 152 to 155 yards, 4 handicap. Coming from the 718 ap2 with project x lz 5.0 weighing 110, the modus weighs 103. We went the same swingweight at D1 with the new irons, but when I got them, they felt heavy and no solid contact.

After reading a lot of material on this, 9 grams in shaft weight can either reduce or increase 1 swingweight. So, since we reduced weight, we should have reduced the swingweight to D0. We tried lead tape down the shaft underneath the grip, but decided to add an additional wrap under the grip, feels good and it was enough to reduce the swingweight to D0+. Feels much better, better contact and more balanced. The modus 105 does feel stiffer than what the weight is IMO, doesn’t have the kick of the project x lz, something I hope I get used to when season starts. These are just my thoughts of what I am going through…I am a feel player, so it’s got to feel right for my confidence in the club. I shall see how it goes. Good luck!!

Th Modus 3 105 in stiff is 13.5 grams lighter than the Modus 3 120 stiff so the swing weight assuming the heads are the same weight would be 1.5 swing weight points lower. Two grams added to the head would add one swing weight point. Also reducing the grip weight 5 grams will add one swing weight point so you could possibly do a combination of the two, however if you have a favorite grip you may not want to make a grip change so just focus on added head weight.