On a 1987 L98 MAF ecm how does the ecm see the VSS signal? 2000 or 4000 ppms?

2000 on MAF TPI
4000 on MAP TPI

so if i have a electric vss and speedo and am swapping in a ecm and motor from a 87 which used a cable i should be able to tap into the buffer of my now TBI car and send a wire from the 2000 ppm side right to the ecm?

Have the guy who programed your aujp change the switch from magnetic vss to optical and use the input from the vss buffer to pin b10 only of the 1227730 it will then except the 2k ppm singal.