If the old VSS has a tell tale sign of Green/Red wire, then it was from an early 1995 and won't work for you. You will need a new VSS and connector (if you threw away the connector from your SVT when you spliced it) .

Note that the signal should be 0 mph:0 hertz, and 55 mph:125 hertz

"Always do the cheap and easy ones first." 1996 V6 ATX 96K miles