Have you done any reading about engine rebuilds? Back in the '80s, HP Books did one called "How To Hot Rod The Smallbock Chevy". (That's what you have.)

I am not expert in electronic injection, so before you try to use a different cam or compression ratio, I would consult someone with knowledge about these things.

I don't know what might be available today. If I were you, I would familiarize myself with the way 4-cycle engines operate, and how the Chevy's are put together.