I am looking for info on a tach, that was removed from a 64 Chevelle SS. It is a 7000rpm sweep, with red line at 6500. Not much room for shifting error given the small 64-65 face. I know it would be easier to post a pic, but the info on how to do that here, is not real clear. Only the beginning of the part number on the back, 64---------. Someone will ask, so, no there was not additional holes drilled to mount in the 64 ss dash and yes, there was a factory loom. This looks exactly like the tachs found in the 6000 rpm tachs, only up scaled to 7000. looking thru manuals of the era, no engines, Small block or BB is rated to shift that high. Anyone have an idea?

If my memory serves me, the 7K tach was for the Z16 option, and the L79 option.
Both of those were produced late 65 though. Maybe Rich L79 will chime in and clarify.

No, no, no, no, no, they were NOT for the L79 or the Z16. First, the L79 and the Z16 used the same tach, the normal 6000 RPM sweep version but they have a 5600 redline instead of the 5200 redline of the more readily available lower HP tach.

The 7000 RPM sweep tach is a bit of an oddball. They do exist since I've owned one and have seen three others. My guess is that Chevy tooled them up for the L76 - 365hp/327ci engine they ALMOST installed in the '64 Chevelle. When the L76 was scrapped for the Chevelle they weren't just going to throw away an inventory of tachs so they installed them in assembly line cars to use up the stock until it was gone. My wild guess is they made a few hundred of them but I have no scientific or documented basis for this guess, it's just a guess.

Part numbers for the regular 6000 RPM tachs:

low hp: 6411826
L79/Z16: 6412504

I believe the 7000 RPM tach has a part number of 6412344.

The 1965 AIM also lists a tach for the L78(?) which was part number 6412218. Maybe this was intended for the Z16 (which technically was an L37 but has the same HP rating of the later L78) but of all the Z16s I've seen I've yet to see one with a tach that is any different than the L79 tach.

Don't believe the 7000 RPM jobbers exist? Here you go:

http://heartland.chevelles.net/RCstorage/7000tach.jpg

http://heartland.chevelles.net/RCstorage/7000.jpg

For comparison, here is a more "normal" L79 tach:

http://heartland.chevelles.net/RCstorage/tachl79.jpg

I need to figure out how to post a picture here. My tach has a redline of 6500. If anyone knows how to post a pic easy , please let me know step by step. Thanks

I've also seen one 7000 RPM tach with a 5600 redline. That was pretty odd.