I have a '92 RS that was gutted of all non used wires when I got it. The speedo/odometer doesnt work since there is no buffer box or any wiring for the vss. I currently have a mechanial speedo trans in it and I want to get the speedo working. Can I buy a mechanical to electronic convertor box and wire it straight to the speedo. i plan on swapping in my '85 dash and wiring to put everything back factory and operational. Thanks for any help.