all the ignition pieces on my truck are stock replacements. just changed the wires, cap, rotor, and plugs. But would a hotter iginition coil such as an Accel super coil help with
MPG and/or power?

 

you need low end torque! A hot coil will help overall, but from experience more low-end torque will help your gas milage. I recently added a 3"in dual 2 1/2" out 50 series flow and watched my milage go down 1 mpg & my low end torque drop as well. Flowmaster recommends a 3" in & 3" out to keep low end torque, not sure what your setup is but if your close to that you should be good on the exhaust side. Too big of an air filter will also kill low end torque, but increase upper end HP.

How old are your O2's? Sluggish O2's will hurt milage as well.
what plugs did you put in? Autolite 3923's are supposed to be good for +5 hp.
Consider MSD 8.5 superconductor plug wires, these have less then 40 ohms/ft compared to 1500 and up on standard wires. This would help with power overall. Less resistance = more current @ the plug for a better spark.