the temperature guage and the tach, and the mpg guage do not work on this one. All the connections match, except the white connector for the temp. there is no conecter. all these were working on my old one except the speedometer, now oppisite. i TRIED PUTTING THE TWO TOGETHER, BUT THEY DON'T MATCH. THE 83 HAD A SEPERATE SI BOARD. THE 84 IS ONE PEICE. HOPE THIS HELPS, IF NOT E-MAIL I'LL TRY TO EXPLAIN BETTER.