If you go electrical which I have in my car youd need a total of three parts 1) the speedo 2) the speedo sensor that screws into the tranny 3) casper's vss converter module to translate from autometer language to Buick language. It gets wired in between the output of the speedo head and the ECM and elimanates the little blue box under the dash . The p/n for the converter is 102046.