My 68'390 GT FB arrived with a dual vacuum advance unit. I had that restored and having found good units hard to come by, I have since found and restored others as spares.
However I recently read on another forum, that the dual advance units were only used from late 1968 onwards...
My understanding was that the correct distributor for a 68' GT390 C6 car is a C80F-D and for the 4 speed, the C (single)?
So is true for all 68' 390 cars, or is there a date where things changed?
Thanks in advance.