I have a blend of old and new in the Novas. Some have a traditional collection of SW and Sun, courtesy of several board members. But, I also use the GM Performance liquid filled units that are made by Autometer. They operate flawlessly and really don't offend my "purist" instincts. Most important thing is, they gotta work!! While we are on the subject, who is a good source for restoring vintage tachs?
wilma
