Mpg 318

I have 318 on my duster. 904, 3.23 gears, second smallest lunati cam, bad headders, its recentry rebuilded about 9.0:1 comp,

HEI ign and one of those cheap summit 600cfm carb

Car gets about 15 mpg on mormal driving 40% town 60%highway.
Longer trips i can get 20mpg if i drive really carefully.


Check timing, then carb tuning, plenty of good info about both in fabo.
whats your idle vacuum and, if you can do it compression test that new motor

And DONT use cars speedo/trip meter to calculate your mpg.
Fill tank full, drive normally and calculate trips you drive from google maps or other similar places, after second fill, you have accurate result.

Ofcours if your normal driving leaves your tires smoking then that 10 mpg is really good:)