Vehicle Speed Sensor effect on tuning

What were the specifics of that swap that was stalling; year of donor vehicle, manual or auto trans used, electronic trans or non-electronic trans originally in donor?
Also as a side note, I had 4x4 Ramcharger with factory equipped throttle body injected 318. The vehicle speed sensor fell apart somewhere around 175,000 miles and I drove it about five more years without a VSS input. The 318 never failed to start, never stalled out, and always had the same power and fuel economy the entire time I drove it.