1971 option U79B??

[Mike E.]

A currently listed 71 LS6 on bring a trailer has paperwork from GM Canada indicating that the car was equipped with "U79B 4-speaker system: dual front, dual extended rear"

I've never heard of this, and have no reference to this in any of the GM documentation I have. Any thoughts on this?

[Bill B.]

Re: 1971 option U79B??

According to the .pdf doc contained at https://www.gmforum.com/attachments/general-gm..., "U79 : SPEAKER SYSTEM, 4, DUAL FRT COAX, DUAL EXT RGE PKG". It does not reference the "B" suffix, so no info on that detail.

I found the .pdf file helpful as a reference, although it does not specify which years are applicable ...

[Mike E.]

Re: 1971 option U79B??

Bill,
In the 70-72 years, U69 is standard AM-FM, U79 is am-fm stereo. I am looking for documentation regarding U79B for 1971 specifically. If the Canadian documentation on the LS6 on bringatrailer is in error, does that call into question the legitimacy of the documentation and the legitimacy of the car?

[Peter M.]

Re: 1971 option U79B??

Mike,
Have you considered calling Vintage Vehicle Services?
I have the phone number and email address if you need it.
Kind regards

[Bill B.]

Re: 1971 option U79B??

Good Question Mike. You might want to contact the seller and have them take a picture of the radio dial on both AM and FM selections to see if indeed the "B" suffix was something special for different frequencies to select on the radio. In the US, the AM band runs from 530 KHz to 1700 KHz, and the FM band runs from 87.9 MHz to 107.9 MHz.

I don't know if Canada was different back in the early 70's or not, especially when it came to broadcasting the FM signal in Stereo. If the stereo broadcast modulation signal encryption was indeed different in Canada compared to the US back in the early '70s, that may explain the "B" suffix that is not listed on our normal GM informational docs, as it would take a different internal demodulation circuit to make it into a stereo output.

As to the "U79B 4-speaker system: dual front, dual extended rear" description they cited, and I'm just guessing here, perhaps the referenced paperwork only had the RPO code with no description and the seller did exactly what I did and obtained the description from the gmforum site's .pdf doc and added it to the documentation description.