67 Transmission Tag Help

[Dereck S.]

I have a 67 M-20 Muncie coupled to a 3.08 rear on my 427/400. It's the original rear and tranny (confirmed markings, dates, VIN derivative, etc) and the configuration is confirmed by my tank sheet. I'm looking for confirmation of the correct transmission tag with the above configuration. I'm missing the tag. General consensus is #3870354. However, LICorvette indicated that they have no information regarding the correct tag for the above configuration. Anyone out there have a 427/390 or 427/400 with an M-20 and 3.08 that can confirm the correct tag before I buy the #354?
thanks,

[Gerard F.]

Re: 67 Transmission Tag Help

Dereck,

How about this one:



This one is on my 67 327/300 with a Muncie 4 speed (wide ratio) and a 3:08 rear end. Guaranteed original.

Not sure that the 427's would be different with the same transmission and rear end. But I learn something every day.

[Dereck S.]

Re: 67 Transmission Tag Help

Thanks Jerry,
I have to believe that the engine configuration was independent of the tag selection and that any 3.08 rear with an M-20 would likely have a 354 tag. Unless I hear otherwise from someone else I'll go forward with the 354. I just had the tranny rebuilt and want to get it back in.
thanks,
Dereck

[Stephen L.]

Re: 67 Transmission Tag Help

The various transmission tag (part) numbers are listed in your AIM on page UPC A1.

3870354=M20 for all drivetrain combinations that used an M20.
3880853=M21 for L79
3880855=M21 for L36 (all BB except L88)
3879987=M22 for L88

[Wayne M.]

Re: 67 Transmission Tag Help

Thanks Jerry,
I have to believe that the engine configuration was independent of the tag selection and that any 3.08 rear with an M-20 would likely have a 354 tag.

Dereck -- your assumptions are correct. This subject keeps popping up regularly (like whack-a-mole) and deserves its own FAQ. Jerry's tag confirms it. ALL M20 wide ratio '67s (and you could get one on base, L79, L36 and L68 engines) would have this tag; and the '354' also implies that the differential was 3.08 thru 3.55. [you couldn't get 3.70+ ratio on any factory wide ratio].

The oft-repeated "'353' for L79" is partly correct. It would also be found on any other engine (except L88) M21 close ratio with a diff ratio of 3.70 or 4.11, incl L36, L68 and L71.

This leaves the '355' for M21 close ratios with final drive ratios 3.08 thru 3.55, incl. engines L79, L36, L68 and L71.

As for the L88's (with M22 obligatory, I believe), 2 different trans tags were possible; 3879987 for 3.08 to 3.55; '986' for 3.70 and 4.11, and if you believe that 4.56 was available through the factory, then the tag would be '988'.

LIC and CC haven't got it right in their current catalog editions.