At tournaments during the year they try to group kids the best they can. At qualifying Tournament this is the official weights.

9 & 10:
52, 55, 58, 61, 64, 67, 70, 73, 76, 79, 82, 85, 90, 95, 100, 110, 120, 130, 150, 170

p.s. If he weighs 174 then he should not be allowed to wrestle, he needed to loose 4 pounds.
If your child looses 3 pounds he will have a better chance.

I don't know about a 140 & 160?