2 cars. CS has tilt, PW, PA. The tach was probably installed long ago when that CS was someone's pride and joy. Could you spec a tach in 65 on a automatic as an factory option?
If 65 was the same as 66 for ordering, the tach was optional on any V8 equipped full size Pontiac and was standard equipment on any 4 speed manual equipped full size Pontiac.
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1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars (now converted to a "factory" 4 speed)