Factory rear speaker mounting

[vegiguy]

How was the original 5X7" rear deck speaker mounted in '71-74 b-bodies? The holes for it look pretty small so I can't tell if they were screwed in from below with #8 sheet metal screws or attached with tiny (about #6) machine screws and nuts, or some other way that is less obvious. I want to add one of these speakers to my car so any help would be appreciated.

 

[Paul_G]

I think that opening was for the rear window defroster. Not a speaker opening, although many use it for a speaker.

 

[vegiguy]

I think that opening was for the rear window defroster. Not a speaker opening, although many use it for a speaker.

I just got done making a separate post on that topic last week. We established that the right (passenger side) opening in the package shelf was the one for the defroster and the left (driver's side), smaller opening was for the optional 5X7" speaker.

 

[Nacho-RT74]

I installed U nuts on panel and used screws to attach the speaker from underside. That will save from remove the package tray. On this case I went for the practical instead correctnes, which I think is install the screw from top side.

( about the single or dual speakers setup on rear... there is still a mistery about that based on some diagrams LOL )

 

[butterscotch71]

I assume your year is the same...here's a survivor 71 GTX. Notice the speaker is mounted from below.

 

[vegiguy]

I installed U nuts on panel and used screws to attach the speaker from underside. That will save from remove the package tray. On this case I went for the practical instead correctnes, which I think is install the screw from top side.

( about the single or dual speakers setup on rear... there is still a mistery about that based on some diagrams LOL )

I don't know what the advantage of using U-nuts is as #8 sheetmetal screws thread right in the holes that are there as long as they haven't been tampered with.

Re dual speakers: I doubt this was an option, at least in '73, because I can't find any dual rear speakers diagrams for B-bodies in my factory service manual; also, one would have to be 5X7" and the other 6X9" if you go by the size of the openings (at least in my car) which seems unlikely.

It looks like a previous owner of my car had tried to install a 6X9" speaker on the left side of my car's package shelf (I assume to match one they had installed on the right side) - even though the opening is for a 5X7" speaker - because there are screw hole drilled for that size speaker. The problem with doing that is that the opening really isn't big enough for that large of a speaker, plus the holes have to go outside of the recess in the shelf so the screw heads stick up which makes it so the package tray doesn't lay down right.

Unfortunately it looks like B-bodies from the early 70's never got very good stereo systems compared to say E-bodies that you could get with I believe something like four or five speakers.

 

[vegiguy]

I assume your year is the same...here's a survivor 71 GTX. Notice the speaker is mounted from below. View attachment 1074844

What type of screws are those that were used to install it? It's hard to tell from the picture.

 

[butterscotch71]

What type of screws are those that were used to install it? It's hard to tell from the picture.

Closeup of the correct screw

 

[vegiguy]

Closeup of the correct screwView attachment 1075008

Is that a coarse thread #8 sheet metal screw with a free spinning washer?

Thanks for posting the pictures. That helps out a lot.

 

[butterscotch71]

old picture, don't have one on hand now. no separate washer, the shoulder is part of the screw

 

[Nacho-RT74]

Similar to the ones used for glovebox liner

 

[vegiguy]

It looks like the same type of screw GM used to mount the inner door handle bezels on 2nd gen Camaros and Firebirds.