Vince,
I'm still not clear as to why you want a Saturday weigh-in so badly. Is it because you don't want to spend Friday night in Topeka or that he is pulling so much weight? I would highly recommend that you take him to the Senior Classic Friday night as it is a great event. If he is pulling a lot of weight the most he will lose over night is approximately 1# anyway. If that isn't enough you should consider moving him up a weight. It will pay dividends later in high school.