I have a 2000 S10 with a 4.3 and the black box computer. Everything is stock on it.

I'm learning this program and this is my personal truck so I'll be able to learn on it beings I'll drive it everyday and notice everything.

I don't have the tun. Off of it yet, but I'm just looking for suggestions for what to start with. What would you guys do first?

If I bump up the timming on everything a safe amount will I get better or worse gas mileage?

Thanks guys,
Branden