Okay, I'm collecting some info here, since after sometime in the next couple of weeks, I won't have everyday access to the Bird.

Recently, I purchased a cordless 7.2V drill, that has a two-speed motor. On high speed, which is 550 RPM, and using my OLD VSS, I read 45 MPH at the speedo. Now, assuming I have a 2.73:1 output shaft to VSS gear ratio, I have calculated that I should be reading 34 (about) MPH at the speedo, if both the math in the Equations section of TGO and my math are correct. Same thing happens if I rotate the VSS from my T-5 at 550 RPM, so I rule out that I have a malfunctioning VSS. At 330 RPM, (low speed for that drill), I should be reading 20.3 miles per hour, as done by the TGO calculator again. However, I read well over 30. I think that number was 32-33 MPH, IIRC.

WTF is up with my speedo? it read correctly using my 700R4, but with the T-5, it's off. I have not altered the dash wiring in any way, except to label the IGN ON power wires going into the fuse panel, for a later project. Is it possible there is some dirt or other crap somewhere in the speedo wiring? How do I check this?