The Supercar Registry - MUNCIE METAL TAGS

The Supercar Registry (https://www.yenko.net/forum/index.php)

- Supercar/Musclecar Discussion (https://www.yenko.net/forum/forumdisplay.php?f=79)

- - MUNCIE METAL TAGS (https://www.yenko.net/forum/showthread.php?t=98292)

Re: MUNCIE METAL TAG ID

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lynn</div><div class="ubbcode-body">From the assy manual for 1969 Camaro (don't know about Chevelle or 67-68 Camaro)

3950356 is for RPO M20 with L48, L34, L35, LM1
3946797 is for RPO M20 with Z28 & L78
3950316 is for RPO M21 with L34
3946798 is for RPO M21 with Z28 and L78
3950318 is for RPO M22 with Z28 and L78

Evidently, from this and from the RPO spreadsheet file in pdf available at camros.org, you could not order a close ratio (M21 or M22) unless you had L34 (M21 only) or Z/28 or L78.

Now, for another question: Why is there a different tag number for the M20 behind a Z/28 or L78 as opposed to the one behind an L48 engine? They would be identical outside dimensions. The Z and the L48 would have identical shifters and brackets. Was there anything internally different between a Z/28 M20 and the regular small block SS M20? There had to be something different about these transmissions to warrant different tags. Maybe the standard rear gear ratio? </div></div>I don't think they had identical shifters.I don't think they had identical shifters. One would have had a Hurst and the other a Muncie.

Re: MUNCIE METAL TAG ID

All the four speeds in 69 got the hurst shifter.

I believe the answer to the question was submitted by crash: "Different speedo gears on the main shaft..." Crash

The Z and L78 would likely have the lower rear axle dictating different speedo gears to at least get close on the speedo.

Re: MUNCIE METAL TAG ID

I noticed above that "<span style="font-style: italic"><span style="font-weight: bold"><span style="font-size: 11pt">3950316</span></span> is for RPO M21 with L34</span>" but I have the same tag on an M21 for a low mile L78 (4.10 rear) car. Would that be possible?

Re: MUNCIE METAL TAG ID

Calling all trans tag gurus.....(see above). Thanks!

Re: MUNCIE METAL TAG ID

An anomaly [img]<<GRAEMLIN_URL>>/dunno.gif[/img] why did they bother with a tag for L34 and L78 ? No differance in the M21, right ?

Mike

Re: MUNCIE METAL TAG ID

Mikey, I agree. I don't understand why there would be a different tag (and for that matter the trans construction) for a L34 vs L78 engine in front of an M21. Referenced car is original engine, tranny, and rear with owner history and multiple dealer and factory docs. What could matter (as far as differentiating M21 variants on the assembly line) is the speedo gear wrt the rear axle ratio.

Re: MUNCIE METAL TAG ID

There are 3 different speedometer drive gears used on the tail shaft in the muncies. The rear axle ratio will determine which one is used. That is probably why the numbers differ. If a speedo reducer adapter was used that may also reduce the number of different tags that were needed. Here is where I found the information, http://home.comcast.net/~chevelleengineer/speedo.htm it could come in handy. Clint

Re: MUNCIE METAL TAG ID

OK so what is 3968012WM ?

Re: MUNCIE METAL TAG ID

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Furback</div><div class="ubbcode-body">OK so what is 3968012WM ? </div></div>

I believe its for a 1970 M22 application.

Re: MUNCIE METAL TAGS

Steve is correct. Pictured is an M22 in a 70 Z28.

Re: MUNCIE METAL TAGS

Re: MUNCIE METAL TAG ID

I have M22 CT 10 spline and 27 spline. The tag on it is 3968012WM. Chevelle is 26 spline input in 1970? Or just LS6 cars? Is this correct? And mine is tagged for 1970 Other cars with M22?

Re: MUNCIE METAL TAG ID

Furback, 3968012 WM Transmission tag was used on 70 Camaro and Corvette M22 applications. It was a 10 spline input with a 27 spline mainshaft.
70 Chevelle with a 454 engine used a 3978766 WO coded Trans which is the 26 spline input with a 32 spline mainshaft for the M22 that they used. This was for both ls6 and ls5.
Chris

Re: MUNCIE METAL TAGS

KA code is 1970 Olds M21.

Re: MUNCIE METAL TAGS

Here is mine on my 1970 Chevelle SS 454 LS6 M22

Re: MUNCIE METAL TAGS

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Stefano</div><div class="ubbcode-body">KA code is 1970 Olds M21. </div></div>

Thanks Stefano.

Re: MUNCIE METAL TAGS

Here's a few I've saved over the years.

Re: MUNCIE METAL TAGS

Matt -- just a few, huh?

Re: MUNCIE METAL TAGS

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: earntaz</div><div class="ubbcode-body">Matt -- just a few, huh? </div></div>

I had another cup full of them somewhere but I can't find them at the moment.

Re: MUNCIE METAL TAGS

Nice collection. Care to sell the WO tag in the upper right corner? PM me if you would.

Re: MUNCIE METAL TAGS

Matt,
Tag, you're it. [img]<<GRAEMLIN_URL>>/crazy.gif[/img]

Re: MUNCIE METAL TAGS

Pun intended..... [img]<<GRAEMLIN_URL>>/wink.gif[/img]

Re: MUNCIE METAL TAGS

Anyone have a 'WM' tag to sell like Rick posted at the top of page 6 for a 1970 M22? Or where to get a good reproduction tag?

Re: MUNCIE METAL TAGS

Does anyone know what application for Muncie assembly 3880853 would fit? My tranny has this tag number.

Thanks, Paul

Re: MUNCIE METAL TAGS

Wow my 70 chevelle L78 was built at the kanzas city plant with a vin number 127777 I almost swallowed my tounge thought it was mine. Then I noticed it was 112777 so close EH
Pj

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 427TJ</div><div class="ubbcode-body">I took this out of my '55. M-21 I think. Looks like a 1970 unit built in October of '69? Anyone help with the decode?

http://i12.photobucket.com/albums/a2...ps6596727b.jpg

http://i12.photobucket.com/albums/a2...psccbb0cc4.jpg

http://i12.photobucket.com/albums/a2...psc848bf7a.jpg

http://i12.photobucket.com/albums/a2...ps0752e3ae.jpg

http://i12.photobucket.com/albums/a2...psd5500f07.jpg </div></div>

Re: MUNCIE METAL TAGS

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: P.J.</div><div class="ubbcode-body">Wow my 70 chevelle L78 was built at the kanzas city plant with a vin number 127777 I almost swallowed my tounge thought it was mine. Then I noticed it was 112777 so close EH
Pj

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 427TJ</div><div class="ubbcode-body">I took this out of my '55. M-21 I think. Looks like a 1970 unit built in October of '69? Anyone help with the decode?</div></div> </div></div>

I would have cut you a sweet deal had it been out of your car.

Quote:

Originally Posted by Chevy2 (Post 965392)

Well, while were at it whats this # 3915077

I just purchased a L35 68 Camaro with that tag (077) last night. So its for a 68 Camaro 396ci 325hp with 307 posi and M20 Wide Ratio Trans.

Old Thread but hope this helps....Dave

I know this is an older thread, but my new ‘67 Chevelle SS L78 came with an M20....I didn’t realize the M21 was even available, and I was too naive honestly to know the difference! But, it’s now obvious to me that without spec’ing the M21 on the order the factory put the M20 into the build as the standard 4 speed. Car was an absolute rocket regardless and I never had any issues with the M20. I’d probably opt for the M21 given the chance to go back in time! Still miss the car to this day! Hardly ever see a Deepwater Blue Metallic ‘67 Chevelle these days! Been looking for it for many years!

Posting From Dale's Site

With Dale's permission, I am posting a link to his older site with a multitude of information on Transmissions and tags. Most tag information at the bottom of the page. Hope this helps:
http://chevellestuff.net/qd/muncie.htm

Paul

3950318 XH. late 69 M22?

Quote:

Originally Posted by the427king (Post 1580775)

3950318 XH. late 69 M22?

It's listed on the first 69 internal code list to come out May of 68.

My 67 L78 has a Muncie M21 with Tag #3879668.

68 Chevelle L35 M20 first 4 pics.
69 Chevelle L78 M22last 2 pics

I didn't see this one on the list. It's a '69 M21. What does the tag tell?

Muncie tag 3857578

The 3857578 M20 tag is not correct for Z16.

It’s rare, used for 65 Chevelle with 3.70 (RPO G75, 96 units) or 3.73 (RPO H05, 293 units) and 1965 Nova with 3.55 (RPO G96, 120 units).

3857577 is a common M20 tag - correct for Z16.

Z16 was originally supposed to get 3.55 or 3.73 but ended up with only 3.31 open carrier. Apparently Posi units were hard to come by in at least part of the 1965 model year. There were 2 designs for Posi in 1965. The first version apparently wasn’t that good. But the later version was used after that from 1965-72.

Thanks to several people (Jeff H. Warren L. and others) for helping me figure this out.

For sake of completeness, below is the message I received, and my entire reply. I did fail to include G75 3.70 10-bolt ElCaminos in that reply though, so I have added that in [brackets] below. Thanks!

Quote:

Originally Posted by bbjohnny (Post 1683348)

Jeff, can you share your knowledge on Z 16 and 65 Chevelle Muncie tags? Z 16’s that I have seen all had 3857577 muncie tags. There is a guy selling a 3857578 tag that he claims is Z16 and if you Google that it seems to come up. Have you ever seen the 578 tag on any of your Z16s? Or do yours all have the 577 tag. Appreciate your help. Thank you.

Great question, and one that I have already researched extensively.

All Z16's came with the 577 transmission. The 578 part number was initially listed in the AIM as for Z16 (which is why is shows up on many internet lists), but that designation was cancelled and changed to 577 on 11-18-64, which was long before any of the Z16 cars were built.

577 is just a regular 65 Chevelle M20 which has the internal speedo drive gear for a 3.31 or higher (numerically lower) rear axle gear. All Z16's had a 3.31 open axle, so the 577 M20 is what they all got.

The 578 p/n is not found in any parts books to definitively say what it was. But my belief is that it is a 65 Chevelle M20 with the internal speedo drive gear for a 3.55 or lower (numerically higher) rear axle gear.

While 3.55's and 3.73's were not available as RPO's in 65 Chevelle coupes, sedans and wagons, [a 3.70 was an available RPO in a 65 ElCamino with a 195HP or 220HP 283; and] a 3.73 was an available RPO in a 65 ElCamino with a 250HP or 300HP 327; and there was also a COPO number to get a 3.73 gear behind an L79; either of which would have necessitated that there be a different M20 transmission unit (with a different part number) that had the correct speedo drive gear inside of it for that axle gear. Again, I believe that was the 578 M20 transmission.

Based on the AIM notations and change dates, my belief is that the Z16 was originally intended to receive a 3.55 or 3.73 posi rear axle (which would have required the correct 578 M20 transmission); but due to inability to get any posi units at the time that those 200 axles were to be built, they downgraded to the 3.31 open gear that all Z16's actually came with. That change in turn resulted in cancelling the 578 M20 p/n designation for Z16 in the AIM, and reverting to the regular 577 M20 unit (which matches a 3.31 gear).

It is also notable that the Z16 page in the AIM where the rear axle part number is listed was redrawn and redesigned on 11-19-64, the day after the transmission p/n change, so that supports the conclusion that the two changes were interconnected.

So you can tell the guy that he still has a quite rare tag -- records indicate that there were only [80 M20 3.70 ElCaminos built (the other 16 were 3-speeds and powerglides), and] 225 M20 3.73 ElCaminos built [the other 68 were 3-speeds], plus however many of the COPO L79/M20 3.73 combos were built, which is probably only a handfull. But it is definitively NOT a Z16 transmission tag.

Jeff

Thanks Jeff.

There is a post earlier in this thread that mentions the 3857578 tag. That’s my reason for posting in this thread.

That part number was also listed in a FACILITIES & PRODUCTION PLANNING DEPARTMENT PLANNING SECTION publication for Z16 use. But as you said, was later removed in the AIM. And it’s not just a Chevelle (El Camino) tag. Used on a small number of Novas too.