Re: So when in 1972 did GM start installing single wall tops?
 

Pete, I will add to the thread and let you work your detective skills with the info from my blazers/jimmys.

Blazer 1, single wall top with a speaker grill on top of the dash.
Blazer 2 single wall with no speaker on top of dash.

Re: So when in 1972 did GM start installing single wall tops?
 

Wish I could be of more help, but this is what I have.

Jimmy 1, single wall top, no speaker.
Jimmy 2 double wall, no speaker.

Re: So when in 1972 did GM start installing single wall tops?
 

This will either help or just add to the confusion...

Jimmy 3, single wall, no speaker on top.
pic 3 is a jimmy I parted with a single wall top.
pic 4 is a body in storage and looks to have a double wall top, but not sure if it is original to it. (can't open the drivers door at the moment either.)

Re: So when in 1972 did GM start installing single wall tops?
 

Eric thanks for posting. I’ll comb through these. I need to jog my memory regarding sequence numbers for GMCs - for some reason I seem to recall the sequence numbers differed and weren’t inline with Chevy but I may be mistaken.

Re: So when in 1972 did GM start installing single wall tops?
 

My Blazer was built in Flint, sequence number 178459, has May dates in under the dash pad and on the NP205. Speaker is located in the dash.

Re: So when in 1972 did GM start installing single wall tops?
 

Thanks for posting. I ran into a guy with a 2wd Flint build 72 had an original single wall (that he swapped for a double wall) no speaker grill in the dash. Sequence was 126xxx

Re: So when in 1972 did GM start installing single wall tops?
 

Here’s another Flint built single wall without pickup style speaker grill atop dash so originally had a speaker beneath the dash. December 1971 build.

Thanks Eric.

Re: So when in 1972 did GM start installing single wall tops?
 

1972 St Louis built 168756!
Speaker under dash and black double wall top when I bought it!
Owned since 1980 with no reason to believe it was not original.
Replaced it with a single wall many years ago.

Re: So when in 1972 did GM start installing single wall tops?
 

I'll dig up some old photos before selling it- was a '72 St. Louis built with double wall top. Actually Mudduck74 bought it but I haven't seen it since.

Re: So when in 1972 did GM start installing single wall tops?
 

There’s definitely a pattern and it’s documented on this thread. Flint switched from double to single walls and the early single walls used the non-pickup, external to the dash speaker whereas later run single wall tops used the pickup style speaker. Makes sense to switch to the pickup style in terms of stock but St Louis doesn’t appear to have followed suit and there’s no definite evidence of St Louis using single wall tops.

What I’d like to know is when St Louis stopped making the 72 Blazer relative to Flint. Flint assembled them until at least May of 72 and probably later. I’m not sure about St Louis.

Re: So when in 1972 did GM start installing single wall tops?
 

72 2wd GMC built in Flint on March 14th 1972 Single wall no speaker
72 4wd Chev built in Flint May 1972 Single wall yes speaker

Re: So when in 1972 did GM start installing single wall tops?
 

All 72 K5s had provisions for both top styles

Re: So when in 1972 did GM start installing single wall tops?
 

Id have to check my Blazer but my 72 Jimmy definitely only had holes for a single wall

Re: So when in 1972 did GM start installing single wall tops?
 

Post pics up if poss. Would be great to see top and bottom shots. Thanks.

The LH rear quarter on my Blazer was replaced with a GM replacement that was not pulled from another K5. It was new but GM. It has provisions for both tops.

Re: So when in 1972 did GM start installing single wall tops?
 

I have a 72 I just bought a couple months ago from Las Vegas. I live in MI. It only has holes for a single wall top. Fortunately I was able to scrape the paint off my door sticker. No speaker hole in dash but looks like theres a mount for one.

Sorry spid is upside down... not sure why it flipped

Re: So when in 1972 did GM start installing single wall tops?
 

Thanks so much for posting. Interesting twist of information. Would love to see more examples. No sign then that the double wall holes were filled in?

Re: So when in 1972 did GM start installing single wall tops?
 

No signs at all. As far as I can tell the quarters are original. Unfortunately I don’t have a single wall for it right now. I have 2 doubles.

Re: So when in 1972 did GM start installing single wall tops?
 

my '72 (St. Louis) has both sets of holes and a double wall. the single-wall holes are 'sorta' filled in.

Re: So when in 1972 did GM start installing single wall tops?
 

Also, single and double wall holes!

Re: So when in 1972 did GM start installing single wall tops?
 

Mine is 165182, so yours is later than mine. Maybe more serial numbers will pin down a better date?

Re: So when in 1972 did GM start installing single wall tops?
 

72 with single wall top

Re: So when in 1972 did GM start installing single wall tops?
 

Thanks for posting.

Re: So when in 1972 did GM start installing single wall tops?
 

Here’s a photo from 1rippen76 that shows the difference between CST and non-CST single wall top to bedside strips. There are two styles each with LH and RH specificity.

Re: So when in 1972 did GM start installing single wall tops?
 

Are the ones on the left the CST? Those are the ones I have

Re: So when in 1972 did GM start installing single wall tops?
 

Correct. These clear the chrome trim that secures the top of the rear panels.