I am going to disagree with you...I have seen 68 390 Auto's with 6K tachs.
I was initially going to respond to your comment of "disagreeing", that I fully agreed with Richard, that 68's only had 8000 rpm tachs. However, before making such a comment, I usually like to check my documentation.
I first looked at my 1960-68 MPC (first attachment). Sure enough, it only shows an 8000 tach for 1968 (same Part Number as 1967 8000 tach). While looking at the 1968 listing, I couldn't help looking at the 1967 (the 1967 Only MPC has the exact same wording less the "replaced by" comment). The way I read this is that 1967 HiPo's
and 4bbl V8's both got the 8000 tach (a little different than what Richard noted). I then checked the 1967 and 1968 Sales Brochures. Both list the Trip Odometer/ Tach Option, but neither addresses whether 6000 or 8000.
Next, my 1967 Salesman's Price Book (second attachment). Note that under the "Tachometer Option", this agrees with what Richard noted (except Shelby's aren't addressed here), in that it only notes HiPo's as receiving the 8000 tach. Unfortunately, I do not have a 1968 Salesman's Price Book to be able to see what it might say.
At this point, I thought I'd check Kevin Marti's "Mustang by the Numbers" book. Well, he lists the Trip Odometer/ Tach Option, but doesn't break it down into how many 6000 and 8000 (makes me wonder if the Marti Reports break it down ?.
So now I was down to one final thought ; the Electrical Assembly Manuals. The 1967, while not saying
when a 6000 was used and
when an 8000 was used, does show a different cluster assembly for each ; C7ZF-10849-B for 6000 and C7ZF-10849-AZ (also shows different Part Numbers with Interior Décor Option for each). Now tothe 1968 Electrical Assembly Manual. Sure enough ; it shows a cluster of C8ZF-10849-E with 6000 and C8ZF-10849-S with 8000.
So, after all of that, it appears that both the 6000 and 8000 were available in 1968 ; question remains as to what determined when each was used.
For 1967, while we knew that both 6000 and 8000 were available, the question now is, were the 8000 only used in Shelby's and if the engine was a HiPo, or could it also be found in any 1967 V8 with a 4bbl carb ?
Hopefully someone has something better to document the answers than what I have found.
Bob
