GM TH400 speedo help for AEM

[Blackmagic94]

Ok so how can i get a speedo to work on a TH400 transmission? The car is a 94 Mustang GT, i have heard of a electro adapter to make my electro ford speedo VSS work on a GM sending unit for a mech unit, but that has to be a simplier and less expensive way to do this.


So lets hear some input.