Thanks! I believe they are the same, except yours has a 6000 rpm range with a 5K limit, and this one has a 7K rpm range, with a 6K limit. Probably different for a different engine package.
1665 impala, maybe hipo 327 this one is a bigblock factory tach installation http://ww2.collectorcartraderonline.com/morephotos.php?adId=82896612