Delco screwed up the Tachometers on the first Sonoma GT's and had to do a fix. Here's the GM Internal Memo:
http://www.sportmachines.com/wiki/tiki-list_file_gallery.php?galleryId=4
Cheers,
Rick "Opie" Waller
http://www.sportmachines.com/wiki/tiki-list_file_gallery.php?galleryId=4
Cheers,
Rick "Opie" Waller