I installed an SPDT switch today to enable switching back and forth from the MAP sensor & VSS. I also switched the PPM to 8000 on the cruise servo to give it another try now that I know how the cruise reacts when hitting the Set button. Initially the cruise would over react, then under react, and repeat. I now know, when setting the cruise to a certain MPG, you need to keep your foot over the gas pedel so it doesn't over/under react. Once it settles, it's good to go. So I gave it a try at 8000 PPM and it works just fine.
Out of curiosity, I switched from MAP to VSS on the fly and to my surprise, it works just fine! All I have to do is reset the speed/MPG and it's good to go. I assume it's working because 8000 PPM is perfectly divisible by 4000 PPM and the servo is seeing every other pulse? Either way, I am really happy I can set my cruise at a given speed or MPG at the flip of a switch