1965 L78 Impala Tachometer

[Rainer]

[ QUOTE ]
Example:
I have a set of NOS 1st design 1970 Chevelle Tail lamp lenses.The Chevrolet parts books say they used part #5963045-LH & 46-RH.The Original boxes show these same numbers stamped on them as well.
When you pull the actual tail lamp lenses out of their original boxes,they have #5963047-LH & 48 on them instead.These two numbers do not appear anywhere in Chevrolet parts literature,yet they do exist and are the proper parts for the 1970 Chevelle application.
This and yours are just some scarce examples of Delco parts numbering anomalys I have seen and heard.

[/ QUOTE ]

I'm going to disagree with you on this one, Rick. The numbers you're referring to on your lenses are numbers for individual components that make up the lens. Look on the front side and you'll also see numbers on each of the red rectangular inserts. Those three components together make up the item referred to by the part number, which can be found in the books. The components were never available separately, and thus were never referenced in assembly and parts manuals.

The number on the tach corresponds to an actual 65 tach part number, but with a lower redline. No anomaly here. Also, he mentioned that the indentations in the tach face that are supposed to be at the 10's are not in the right places. I noted the indentations in this edited photo. If you look closely, you can see them. This tach face was originally a 6K version, which corresponds to the part number on the backside.

[mssl72]

Well, that's very strange that the zoomed pic shows a pretty good "5" at the end of the part number. So, going by the parts book (it's not listed in my March 1966 parts book) I'm at a loss to say what it's for. It looks like a '65 tach but with that part number, . My experience with 1966 tachs would lead me to the same conclusion: that the GM parts number stamped on the back of the gauge would be the same as what's on the box. I haven't seen them any other way. The tachs in 1966 were made by AC (as most if not all the gauges and senders were) and I would guess that the '65 ones were too. If I find out anything else I'll post it.

[L78Impala]

Ok...here it goes. I did not get a chance to look at the number on the back. I've been having trouble with the photo.

[Mr70]

Yep...you're completely correct Rainer.
I was totally wrong and stated misinformation there.
I was wrong to compare this example to others not connected to it.Your explanation makes sense.
As for the Tach,you're right there too.
I still would like to know what No. is stamped behind Bills?
I'm Sorry for the misguided reply.
Rick

Here's Bills Pic again.

[real_fast]

Thanks for the Picture of the 7K, very nice! It clearly shows a unique face plate inpression as opposed to mine which has the 6K impression as illustrated by Rainer.

So now I need to understand more about the stamp. Are you saying that the part number corresponds with a 6K tach and was never meant to be a 7K tach, that the face has been rescreened?

[Rainer]

Rick, I was only partially correct. Real_fast, the face is definitely from a 6K tach - that's for certain. I didn't notice the discrepancy in your part number beyond the last digit. The number stamped on the backside does not correspond to any of the 4 listed numbers as was indicated previously. The number on the backside of this tach is 6412295. There's one digit off in one of the last two positions - take your pick. Given that the face has been altered, I suspect that the stamp may also have been faked but with an error. The other possibility is a stamping error at the factory, as Rick suggested. In either case, this tach did not start out as a 7K unit.

[real_fast]

That confirms it alright. I think it's silly someone would go through the trouble of stamping a fake number on the back. Anyhow thanks for the education. This info will be useful for others who want to know what they have and to be aware of fakes.