Hi Doug,
I'm Forrest. I'm here to tell you that you can and will do just fine with your proposed 17# jump if you decide to do so. Here's what I would suggest: Begin shooting your current bow more and more. If your current practice session is 50 arrows ease it up to 75, then 100, then 150. This will build endurance in the muscle groups which will be necessary for the building of the muscle mass needed to draw the increased load. When you do receive the heavier bow, work it into your practice session after a good pre-stretch and warmup exercises. I like to follow the rule of only going down in weight during practice. When you are over bowed in the beginning, I cannot stress this enough. The inability of the mind to get over the noticeable increase in workload when the body is tired causes recruitment of often unprepared muscle groups and creates an inroad for potential injury. I set goals of six shots and later twelve shots, sticking strictly to the limit and stopping at the slightest discomfort. Stretching at the end of the session is helpful to avoid discomfort and soreness later.
The biggest thing I would stress is that you and you alone decide what is doable or too much. Their will always be someone to tell you that you can't or shouldn't. God never made a naysayer that could keep quiet. Believe you can do it and you will do just fine with your bump.
I'm no health and fitness expert, but I was able to increase my draw by fifty pounds using this method over six months time and was injury free. I wish you the best whatever you decide.
Forrest