I acquired seven TaylorMade SLDR 57g senior iron shafts, 41.5″, no trimming instructions included. I am building 5 thru GW with Adams XTD heads for a left-handed 75 yr old. He is a former professional tennis player and a good athlete. He usually shoots even to 4 over on our local 3200yd 9-hole track. He would like the clubs to be as stiff as possible. How should I tip trim the shafts to achieve this?