I did use a liberal amount of themal barrier and dry film lube ooatings in my 440 build. I also spent considerable time dialing in the carb tune and ignition curve.

I didn't go efi or overdrive because the return on investment didn't seem like it would be there. I had gone from a tired old beater with 8 mpg to a freshly rebuilt engine and driveline at 18 mpg .Dumping another 3-4 grand to get into the low 20s didn't seem worth it to me.

Now if you already have a good engine and trans in the vehicle that don't need to be reuilt, then efi and overdrive may be the next logical progression and make more sense.

However, building an engine for a huge, pool table flat torque curve means you have enough torque to overcome the lack of additional gears in the transmission and do not need to build to a narrower rpm range to get good mileage.