Dating C-3 Horns (You know what I mean)

[Martin N.]

I just aquired a pair of horns off of (I was told) a 1974 with option code U05. Anyone out there that can tell me if these look legit? Are the #'s OK and what about the mounting brackets, they don't quite match what's in the Assembly Manual, which I've encounted this problem before. The 2 on my car do not work and are rusted beyond belief. These 2 work and are ready for restoration.

Numbers: 1447F5 A and 1457H1 hiFa

Thanks,
Marty

[John F.]

Re: Dating C-3 Horns (You know what I mean)

Call Ron Goralski (410)987-1948. He is the horn guru and rebuilt the horns on my 62. Highly recommend.
John

[Chuck S.]

Re: Dating C-3 Horns (You know what I mean)

I just aquired a pair of horns off of (I was told) a 1974 with option code U05. Anyone out there that can tell me if these look legit? ...Numbers: 1447F5 A and 1457H1 hiFa...

Marty, earlier C3 horns were dated numeral (year) + alpha (month) + numeral (week of the month). Yours have three digits proceeding this format; I don't know what those digits could represent unless it's the last three of the part number.

In my opinion, these dates do not appear to work for a 74. The "7" probably represents 1977 since dual horns were standard prior to early mid seventies. But, U05 was not offered as an option on 76-77 Corvettes, which may explain why the brackets are slightly different from the ones on your car; i.e. the horns may have been used for U05 on another 1977 Chevrolet product.

[Jack H.]

Re: Dating C-3 Horns (You know what I mean)

From what I can tell, the change over in horn stamping sequence came about in 1977. At least through 1975 the sequence was the full horn PN followed by a three character, alphameric, date code sequence.

The '77 and later horns had a different construction (mixed metal/plastic housing) and they were stamped/embossed with a single six character sequence. The first three digits of the sequence correspond to the last three digits of the PN and the following three digits are thought to represent a form of Julian dating.

NCRS descriptive text does NOT decode the Julian sequence, but with a 3-digit field it would have to be in the format WWY or YWW. From what I've seen on later Shark cars, I suppect the format is WWY...

[Chuck S.]

Re: Dating C-3 Horns (You know what I mean)

...NCRS descriptive text does NOT decode the Julian sequence, but with a 3-digit field it would have to be in the format WWY or YWW. From what I've seen on later Shark cars, I suppect the format is WWY...

For 70-72, at least, the NCRS text (TIM&JG) says the date code was Year/Month/Week, with the month being the middle alpha character described in a table; A=January, B=February, etc. An example given in the TIM&JG: "A 1H4 date code is 1971, August, 4th week."

I would have sworn that my 70 horns were completely die cast painted black, and were dated Julian day of the year with a single year digit, but perhaps my recall is faulty. The TIM&JG says that 70-72 horns were constructed of black plastic and metal painted semi-gloss black, and that 71/72 had one horn, where 70 had two (knew that already).

Being right on the date format and construction, and at odds with the TIM&JG, is not important enough to me to dig them out...I'll reserve that crusade for another day. Perhaps GM totally scrambled the dating system for horns beginning in 77, but that would surprise me. In any event, my opinion is...regardless of the date code format, none of those characters on Martin's candidate horns works for a 74.

[Martin N.]

Re: Dating C-3 Horns (You know what I mean)

For 70-72, at least, the NCRS text (TIM&JG) says the date code was Year/Month/Week, with the month being the middle alpha character described in a table; A=January, B=February, etc. An example given in the TIM&JG: "A 1H4 date code is 1971, August, 4th week."

I would have sworn that my 70 horns were completely die cast painted black, and were dated Julian day of the year with a single year digit, but perhaps my recall is faulty. The TIM&JG says that 70-72 horns were constructed of black plastic and metal painted semi-gloss black, and that 71/72 had one horn, where 70 had two (knew that already).

Being right on the date format and construction, and at odds with the TIM&JG, is not important enough to me to dig them out...I'll reserve that crusade for another day. Perhaps GM totally scrambled the dating system for horns beginning in 77, but that would surprise me. In any event, my opinion is...regardless of the date code format, none of those characters on Martin's candidate horns works for a 74.

CHUCK-

The horns I aquired are metal & plastic. The 73-74 TIM&JG only states that the horn(s) are "semi-gloss black with a part number & a 3 character date code stamped on the back." It does not mention what the horns are constructed of. Maybe someone could post a picture from a known original 74 horn or even a Service Replacement Part. I'm now starting to believe that these 2 horns are from a 77 or 78 model year. Since mine are inoperable I will restore these for temp. use and keep searching, I guess. Thanks for your input.

Marty

[Chuck S.]

Re: Dating C-3 Horns (You know what I mean)

...The horns I aquired are metal & plastic. The 73-74 TIM&JG only states that the horn(s) are "semi-gloss black with a part number & a 3 character date code stamped on the back." It does not mention what the horns are constructed of...

I might have misled you with my comments, of which all weren't really relevant to your question. I would not argue with ALL Corvette horns after 70 being made of plastic and metal; I just don't remember that type construction on my 70 horns.

The 70-72 TIM&JG does indicate different part numbers for 70, 71 and 72 horns, possibly opening the door for different construction. I can remember masking the trumpet opening grit tight and bead blasting them for paint, but I don't remember any plastic on the horn. I'll see them again some day.

Since the horns appear to be functional replacements, and your originals are toast, giving them fresh paint and using until you find something better is a good strategy. You may even be able to swap the brackets around...my parts book had a note in that regard; all low note horns, 55-72, and high note horns, 55-70, are the same two service part numbers by 1972, but the mounting brackets were different requiring reuse of the old brackets.

I wouldn't put a lot of money into having those horns professionally restored, but that's your call.

[Martin N.]

Re: Dating C-3 Horns (You know what I mean)

I might have misled you with my comments, of which all weren't really relevant to your question. I would not argue with ALL Corvette horns after 70 being made of plastic and metal; I just don't remember that type construction on my 70 horns.

The 70-72 TIM&JG does indicate different part numbers for 70, 71 and 72 horns, possibly opening the door for different construction. I can remember masking the trumpet opening grit tight and bead blasting them for paint, but I don't remember any plastic on the horn. I'll see them again some day.

Since the horns appear to be functional replacements, and your originals are toast, giving them fresh paint and using until you find something better is a good strategy. You may even be able to swap the brackets around...my parts book had a note in that regard; all low note horns, 55-72, and high note horns, 55-70, are the same two service part numbers by 1972, but the mounting brackets were different requiring reuse of the old brackets.

I wouldn't put a lot of money into having those horns professionally restored, but that's your call.

Exactly Chuck, since these horns work I'll do the rust removal, prime & paint myself and hunt for an original pair. Thanks.

Marty