new chain n sprocket time. lots o questions...

In all honesty I've never really cranked the rpms in any gear aside from 2nd entering expresswaysv and usually shift well before 6k in the other gears. I think I'll have to try taking a spin in the high revs before deciding on changing anything after running the numbers on gas savings and found it to only be around $25 per 1000 miles. This is all new to me so I really appreciate the experience and advice of the members here.