VSS Question

A bit confused here about what to do regarding VSS. My first TBI conversion is using a 1227747 ECM and is going in a 78 K15 with a TH350 transmission. Donor vehicle was a 1991 Chevy 1500. I'm mapping the wire harness but don't know for sure if I need an aftermarket VSS as I thought I read where the P/N wire can be grounded. I'm ok with buying an aftermarket VSS if it will improve drivability, just don't know which one to get. Can anyone recommend a part number from JTR's website? Thank you.

Can you upgrade to a speedometer from a newer truck that has cruise control? I'm not sure if your year has it but my 85 had cruise control with a optical vss behind the speedometer. this would be the cheapest and easiest way to go and i feel like you can swap gauge clusters from 73-87. It would only be a 3 wire hookup then, ignition, ground, and vss to the ecm.