Here's the start, but I never read it all. Guy in basement lab splices genes (grasshopper, more?) into his to be born son. Kid grows ok, but superstrong and ends up killing an opponent on the football field. Any help appreciated!
I have ordered the book, but have not gotten yet so I'm not sure. I remember it as some kind of injection. I also remember reading stories from that time of people building spaceships in their garage. Naive, but a lot of fun. When I re-read it I'll post again.