So my 94 is having what I think is timing issues concerning the timing advance. The truck stays constantly 20 degrees advanced at idol and under heavy load and anything inbetween. My MPG is lacking and it is lacking power under heavy load starting off the line. The truck is timed correctly, disconnected the wire under the dash to time it and everything. Is this normal or is something wrong?

Also, I'm looking into a performance chip to help with MPG's and power. To me after I give it past 50% throttle it feels like the fuel is being limited cause the truck wont give anymore after 50% throttle.

What kind of chip should I look into? I've looked at Jet Chips but they wont respond to any of my question.