Ray, what kind of RPM's are you turning at 55 and 65 with your current setup? Is the 413 mostly stock, or do you have a cam, headers, ??? What kind of mileage do you get with your rig?
2700 @ 55 3200 @ 65 BTW the truck versions had a governor set at 3,400 RPM redline!
All stock except HEI and hot/cold air cleaner snorkel ~9-10MPG working on the code for a RaspberryPi dash computer with fuel meter (I added O2, vacuum, drive shaft, spark and crank sensors)