318 2bbl to 4bbl: Is it worth it this time?
MOPARJ;
I noticed a small plug in section on the opposite side of the box. Could this be where the tach lead that normally connects to the coil should go??? How can I get the tach to work normally with the box?
Yes. IIRC, the tach hook up is at the other end of the MSD box, a little male connector counter sunk inside the box's housing. That should set it straight.
The list or search for extra mileage is long. Some if not many you have done;
From top to bottom, front to rear;
Open air cleaner. I like a large diameter and as thick as one can squezze under the hood. It's simply more area, thats all.
No matter the carb, though I prefur a T-Q or simply a Carter, it needs to be dead balls on. F.I. would be best, because the carb will fall in and out of tune with the days heat or lack there off.
Upgraded intake. Blocked heat cross over. Sometimes a spacer can help between the carb and intake. A single plane should, in my head at least, get better Hwy. mileage.
Heads...well, actually, VALVES and seats. Even a simple clean up by your own hands is great on older engines with alot of miles. Since yours in new/rebuilt, a back cutting of the valves and seat work to improve flow can help breathing.
Cam...OOOOOO, tricky one. The thing with stock engines is the exhaust. It is in need of help. A split duration cam can help it breath easier. One day I'll have a few spare hundred bucks to have made a few custom grind cams with really small intake durations in a search for more mileage, but with extended exhaust duration which will not only help power, but IMO, mileage as well.
Headers, X pipe, dialed in distributor, and upgraded ignition,, parrasidic lose minimized, mechanical fan deleate, P/S delate, O/D tranny, or beter yet, manual O/D conversion, Hwy. gears, taller thinner tires, fiberglass wieght reduction and anywhere else you can get it on the body or drivetrain and wheels. Sythn. oils
The list goes on and on and on and on.......