318 MAX fuel economy builds?
Years back a fella on Moparts did a mileage 318 build. IIRC, he was able to achieve 32 mpg’s. I don’t remember the details of everything, but, again, IIRC, he used a high compression ratio to help.
IF I myself was going to do this, and I have thought about doing it for fun, I’d look towards the following parts.
@Bewy recommendation of a small primary TQ
The factory 4bbl. or a SP2P though they’re hard to find.
An Edelbrock Performer would also be a viable intake.
Stock cylinder heads with a 3 angle valve job.
Earlier years 318 pistons for more compression due to the pistons height. A KB replacement flat top is also a good idea.
Iskendarians (Isky) Mile-a-more camshaft
That would be the list of basic starting engine parts that should do very well. The transmission would be A lock up 904 or a LU/OD 904.
Gear ratio with the 904 would be a 2.45 if I could find one. Or work the math backwards with the OD trans ratio to find a suitable ratio to end up numerically as low as the 2.45.
A multiple spark ignition is something I have found helpful in low speed, low rpm driving in order to burn the most fuel possible for added mileage. While I have had the most crappiest luck with MSD, only one box worked longer than 30 days…. A multi spark box is a great help.