1966 L72 Biscayne

[fsc66]

No you could not get a 327 with an M21, I posted the Power Team chart, find on there any other engine than an L72 that lists the 4-Spd Close Ratio Trans???

Paul Winvoices

[AdamApple]

hello folks.
after consultation with some others, i am being told what i have is a true L72 due to the 2Q code, the date correct M21 and date correct 4:88 12 bolt, exactly as some of you noted.
i also failed to mention the car has a transistorized ignition, which also makes sense.

if anyone would know where i could source what i'm missing, like the tach, idler pulley, correct exhaust manifolds and date correct original block, i would be really appreciative.

also, id like to register this with the right group and/or find out if the car is already registered.
anyone know how to go about that?..

any help would be appreicated

[TAR6569]

It's in my research database from when I previously saw it for sale. Nice to have the extra data! Can you get a pic of the partial vin stamp on the front, side of the trans, opposite side from the date code? Also, look for a metal part number tag attached to one of the side cover bolts.

It's one of the last L72's built for 66. Janesville production ended 2nd week of June but your vin, 6J301893 is only 42 from the end of production there, which was 6J301935!

I have data on 22 66 L72 2nd sedans

[AdamApple]

wow!
that's great info and great to hear.
i will carve out some time to get under there and get those things you are asking for.
gimme a little time and i will.
thanks again!

[TAR6569]

Are you near Albany NY by chance?

[AdamApple]

im not, actually.
im downstate in the boros.
whats up?

[TAR6569]

my brother is up near Albany. Thought maybe he might run into you at a local cruise night

[AdamApple]

i have family up in Troy, but i'm not getting up that far with 4:88s...lol

[mssl72]

So anything 1966 full size L72 gets my attention, so I was following this thread. The transmission discussion brought up things for me again and I found a document I had been putting together and thought I would post it.

Transmissions in these cars and the cowl tag always puzzled me some. L72 full size cars in 1966 were available with M20, M21 and M22. There was also the 3 on the tree option too. In regards to the M22 in full size cars, GM documentation says only 2 cars were produced at the factory. While close ratio transmission cars had a "2Q" as an indicator and wide ratio transmissions had a “2L”, it seems that not all plants used the same codes, especially BOP (Buick-Olds-Pontiac) plants.

I always wondered why Fisher body needed to know if the trans was close or wide ratio. I figured all they needed to know is if it was going to get a 4 speed or automatic. I had a conversation with Leigh Scott (who is a '66 Full size fanatic and retired GM 35+ year employee) about it and he said;

"All transmissions in 1966, except for Muncies, the speedo cable came out on the drivers side. The Muncie for '66 came out on the passenger side. In 1965, for the M20 Muncie, the speedo cable came out on the drivers side, the M21 came out on the passenger side, hence the reason (I believe) for the "Q" to denote the close ratio M21 and the need for the passenger side speedo cable clip on the floor pan. Old habits die hard, so that's why I think the "Q" lasted for 1966.”

He also mentioned that the rear axle gear ratio had an impact on if the trans would be close or wide ratio. It seemed that cars with low gear ratios got wide ratio transmissions. Paul (fsc66) posted documentation to reflect this as well.

So over the years I’ve kinda built a little list of 1966 L72 Caprices. The trans codes and gears didn’t always jive and I believe that Leighs reasoning on the codes makes sense.

Here are some known examples:

3.31 (DH code) and an M20 no trans code on tag (Doraville BOP plant built) 04D 16647 Caprice
3.73 (DM code) and an M21, 2Q on the tag (Atlanta plant built) 01B 16647 Caprice
3.73 (DM code) and an M21, 2L on tag (Norwood plant) 12C 16647 Caprice
4.10 (DN code), 2L on tag, wide ratio? non original M20 installed (Norwood plant) 01A 16647 Caprice
4.10 (EH code metallic brakes) and an M21, 2Q on tag (Los Angeles built) 12B 16647 Caprice

Adam, your car sounds like it’s on track. The K66 TI option is a nice piece. To see if you can locate some parts you’re missing I would contact Leigh Scott via his website. He’s a great guy, full of knowledge, and does insane restorations.

https://www.detroitautomotiverestoration.com/

I am curious if you can post some closer pictures of the air cleaner, the snorkels and bottom. What is the exhaust system like, is it original, where do the tailpipes exit? The radiator looks correct. Remove your washer bottle and take a look at the side of the radiator with a good light and see if there’s a number stamped on it. If it does let us know what it is. What is the stamping on your alternator (that pulley isn’t correct, alternator could be)?

[LT1vette]

I knew they were available with all 3 trannies. M20/21/22 Contrary to what the GM literature and Paul say.
I know the owner of 1 of the M22 cars. Almost every option on that car...