MUNCIE METAL TAGS

[Lynn]

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?

[crash]

Different speedo gears on the main shaft... Crash

[hubleyman]

So after reading this topic of discussion, I decide to go out in the garage and check out the tag for my 69 Z/28 and see if it has that 3946797 tag that is being discussed...

Mind you, this Muncie is the matching number gearbox for my car but has been sitting under a workbench for 15 + years (my buddy who used to own the car broke one of the mounting ears). I've never bothered to look at it other than to make sure the VIN was correct....

Low and behold, here's a pic of what I found....

Charlie

[Lynn]

Nice! You didn't even know you had a rock crusher? Can you post a pic of the assembly date code?

[hubleyman]

Oh sure, make me get my hands dirty.......

Well, with a little help from some carb cleaner, here you go.......

FYI, my car is a 10A Norwood built Camaro so I think that is before they started stamping the extra trany code letter on the case??? Probably why I never bothered to open the side cover and check it out? Looks like I have a new task to do this weekend....

[Charley Lillard]

Or save yourself the time and effort and give me the Z28..

[hubleyman]

I'd be happy to Charley.... but it was dirty last time I had it out it wouldn't go to well with the others in your Harem....

<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 &amp; 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.