Honda 300ex sprockets ?

Hello! My son has asked for new sprockets for his quad for his birthday. He’s sent me a link to 14 tooth JT steel for front and 37 pro taper for rear. Do those sound correct to you? Also, I hear he should probably get a new chain as well with the new sprockets? Any recommendations there?

He’s able to do some work on the quad himself, so I’m guessing he knows if these will work, but I just wanted to make sure. He lost both his dad and his uncle in the last year and they were his “quad guys” for help and maintenance. I used to ride 300ex/400ex, but never did the work. Just trying to make sure he’s doing the right thing.

I appreciate your help!