I have 3 Mentor's. 1 is the new B-model that Wes hasn't told many about. I have 49#@28 66", 55#@28" 62", 60#@28" 64", 60#@28" 60" limbs. With the 60" limbs on my B-model riser the bow is a 56" incher. It is awesome and is 61#'s on that riser. Perceptibly faster than anything I have. The working length is the same as the 19" riser and shoots very close to the others in how it feels. But it does start to stack after about 28" which I draw just short of. This is perfect for me. The 19" riser, the normal Wallace Mentor, from my experience and from those who I know shot my bow with longer draw lengths have never complained about stacking. I would say in absolute confidence at 29" you should not feel stacking. How much further I could'nt say? Seriously, if you were at all concerned, look at both of your hands and look at your thumb and pointer finger. Measure an estimate of 1" on both hands and look how much more room you will need to hunt with. Not a lot. My friend has at least a 29" draw and shoots a WW 62" and never complains of stacking. He shot my 60" limbs on both the 15" and 19" riser. He only felt it on the 15". You will not be sorry with WW bows. I sold everything I have just to shoot his specifically. He is a world class bowyer as well as a world class guy. Buy from him with complete confidence. Let him know your concern, he will help you and he WILL stand by you if you have a problem. You could always sell a set of limbs like the ones you want very easily. Maybe more than 2cents worth, just my thoughts.
Kenn