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I have a '68 L71 with the original M22 'Rock Crusher' transmission (1 of 80), and 4.11 gears. Would anyone know how many of these 80 are actually in the L71's? I can only assume most were in the L88 & L89's..
All 80 M22 optionally ordered transmissions in 1968 were a mandatory ordered part of the L-88 package. No L-71/L89 ordered Corvettes in 1968 or 1969 ever were equipped with a M22 heavy duty 4 spd transmission.
All 80 M22 optionally ordered transmissions in 1968 were a mandatory ordered part of the L-88 package. No L-71/L89 ordered Corvettes in 1968 or 1969 ever were equipped with a M22 heavy duty 4 spd transmission.
I wondered about that...Thanks. The 3 previous owners provided hand written documentation that the M22 was original, but the original tank sticker only partially shows "M2_...cant quite make out the rest. I guess I'll have to find the transmission stamp, as I dont think the Protect o plate identifies it. Appreciate the info!
I wondered about that...Thanks. The 3 previous owners provided hand written documentation that the M22 was original, but the original tank sticker only partially shows "M2_...cant quite make out the rest. I guess I'll have to find the transmission stamp, as I dont think the Protect o plate identifies it. Appreciate the info!
So the L71 was only availible with the M21 Close Ratio 4-spd. I'm going to check for the 4.11's..
Check for the VIN derivative stamped on your transmission.
I'm still confused?...
1968 - 1969 1" Bore Patent Number (3) Colvin's "by the numbers" book notes that Muncie data shows 1968 and 1969 M22 transmissions received main case #3925661. All documented M22 transmissions have the #3925660 main case. It is unclear why there is the discrepancy.
PIC 1
STAMP#3925660
US PATENT NO 3088336
(AND DRAIN PLUG)
=M22? (NOT FACTORY)?
PIC2
PARTIAL VIN AND P8S09
=FACTORY? MUNCIE NOV09 1967
GM docs all say that the L71 engine was only available with the M21 transmission, so I would be shocked to find you have something other than that. It is simple to add a drain plug and many have done it, so that is not a reliable indicator of an M22. Even the gears can be easily changed.
For 1968 and early 1969 you can't tell if it is a M20, M21, or M22 from the POP or transmissions stampings. They simply tell you the date the transmission was made and the car vin it was put into. Later in the 1969 model year they started stamping A, B, or C at the end of the date to denote the type.
Does your transmission still have the metal tag with the part number on it? With this you should be able to determine M21 vs. M22.
Your rear end code of FA on the POP is a HD 3.70 rear end used in BB applications.
John
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GM docs all say that the L71 engine was only available with the M21 transmission, so I would be shocked to find you have something other than that. It is simple to add a drain plug and many have done it, so that is not a reliable indicator of an M22. Even the gears can be easily changed.
For 1968 and early 1969 you can't tell if it is a M20, M21, or M22 from the POP or transmissions stampings. They simply tell you the date the transmission was made and the car vin it was put into. Later in the 1969 model year they started stamping A, B, or C at the end of the date to denote the type.
Does your transmission still have the metal tag with the part number on it? With this you should be able to determine M21 vs. M22.
Your rear end code of FA on the POP is a HD 3.70 rear end used in BB applications.
John[/QUOTE
The metal tag isnt where it should be. Does this different casting no. mean anything? 38996621
Last edited by Alxnaj; Apr 27, 2015 at 10:03 PM.
Reason: typo
I have a 1968 327 / 300 hp with what looks like a M22 Transmission. I have attached a picture the vin number matches the engine and the car. Can you please confirm.
Originally Posted by JC68
Alxnaj
GM docs all say that the L71 engine was only available with the M21 transmission, so I would be shocked to find you have something other than that. It is simple to add a drain plug and many have done it, so that is not a reliable indicator of an M22. Even the gears can be easily changed.
For 1968 and early 1969 you can't tell if it is a M20, M21, or M22 from the POP or transmissions stampings. They simply tell you the date the transmission was made and the car vin it was put into. Later in the 1969 model year they started stamping A, B, or C at the end of the date to denote the type.
Does your transmission still have the metal tag with the part number on it? With this you should be able to determine M21 vs. M22.
Your rear end code of FA on the POP is a HD 3.70 rear end used in BB applications.
I have a 1968 327 / 300 hp with what looks like a M22 Transmission. I have attached a picture the vin number matches the engine and the car. Can you please confirm.
You have started a thread on this, please do not resurrect a 6yo thread just to repeat your question.
I have a 1968 327 / 300 hp with what looks like a M22 Transmission. I have attached a picture the vin number matches the engine and the car. Can you please confirm.
You are posting your question in answer to a post from 6 years ago. I’d tell you to start your own thread but it appears you have done that already. Let’s keep your responses confined to that thread.
M22 Question
