318 mystery problem, somewhat solved!

Just a bit confused by this comment.

" when you hit the pedal and power comes on, there just isn't any power there."

You say you retimed and retuned to get better mileage. What kind of mileage do you get now?

As far as the 318? Well I owned a 69 340 Swinger and the next car I owned was a 74 Plymouth Duster 318. Both bought brand new and both basically stock with the exception of the 340 getting a dual point diss. When I hit the loud pedal on the 340 I knew it. When I hit the loud pedal on the 318 I just got bored waiting for something to happen. If you are tuned for mileage, then my guess is you got what you want.

Did the car have more power before you tuned it for mileage? What changes can you make re mixture based on throttle position and load?