1971 LT1 question
Thread Starter
Racer
Joined: Aug 2003
Posts: 406
Likes: 68
From: San Clemente
1971 LT1 question
I have a 1971 LT1 convertable , all numbers match, I have done some research on the car and hit a wall, The car has a M22 in it, I know only 7 - M22's went into the LT1's in 1971, does anyone know how many went into the convertable LT1?
Race Director
Joined: Dec 1999
Posts: 19,610
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From: Forked River NJ
I think your numbers are a little off. There were 8 ZR1s made in 71 which all had M22 trans. There was a total of 130 M22s installed in 71 cars and I'll bet a lot of them went into LT1 cars. How many were Verts they did not keep that detailed records back then.
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1971 production statistics from "Black Book":
total M22 = 130
total LT1 = 1,949 (350/330hp)
total LS6 = 188 (454/425hp)
total ZR1 = 8 (LT1 engine package includes M22)
total ZR2 = 12 (LS6 engine package includes M22)
Since the M22 was only available in the LT1 and the LS6,
I'd say you probably have a pretty rare option.
20 of the 130 went to ZR1 & ZR2 options.
so how many of the remaining 110 M22 went
to LS6 (188-12=176 left) and LT1(1,949-8=1,941) .... ??
Since those figures are not available,
I'd guess many of the LS6 cars had a M22, leaving only
a handful of LT1 cars with the M22.
You should also verify your car to see if it was a ZR1 ...
ZR1 included LT1, M22, TI, heavy brakes, Alum radiator,
metal shroud and special suspension.
(ZR1 did NOT have P/W, A/C, A/T, PO2, Alarm, radio)
nice car!!!
total M22 = 130
total LT1 = 1,949 (350/330hp)
total LS6 = 188 (454/425hp)
total ZR1 = 8 (LT1 engine package includes M22)
total ZR2 = 12 (LS6 engine package includes M22)
Since the M22 was only available in the LT1 and the LS6,
I'd say you probably have a pretty rare option.
20 of the 130 went to ZR1 & ZR2 options.
so how many of the remaining 110 M22 went
to LS6 (188-12=176 left) and LT1(1,949-8=1,941) .... ??
Since those figures are not available,
I'd guess many of the LS6 cars had a M22, leaving only
a handful of LT1 cars with the M22.
You should also verify your car to see if it was a ZR1 ...
ZR1 included LT1, M22, TI, heavy brakes, Alum radiator,
metal shroud and special suspension.
(ZR1 did NOT have P/W, A/C, A/T, PO2, Alarm, radio)
nice car!!!
Melting Slicks
Joined: Nov 2004
Posts: 2,672
Likes: 6
From: Nevada City California
Jermo,
You've been given some good information. I've been involved with surveying and registering the 1971 LS6 Corvette information. We currently have 85 cars verified, so we are approaching the 50% mark.
Of the 130 M22 transmissions sold during the model year 1971, eight were installed in LT-1 ZR1 Corvettes. I believe the breakdown is 4 convertibles and 4 coupes. I know of at least 4 of these cars. The other 122 transmissions went into the LS-6 cars. Twelve went into the LS-6 ZR2 optioned cars, we now know of 7 of the 12. The other 110 transmissions are in regular LS6 Corvettes. This leaves 78 LS6 Corvettes that were either ordered with TH400 transmission or the M21 transmission. Currently we have 12 LS-6's built with automatics and another 12 built with M21 close ratio transmissions.
M22 transmission equiped LS-6's use the HD dual plate clutch set-ups as part of the package. M21 transmissioned cars have been seen with the standard 11 inch clutch.
You've been given some good information. I've been involved with surveying and registering the 1971 LS6 Corvette information. We currently have 85 cars verified, so we are approaching the 50% mark.
Of the 130 M22 transmissions sold during the model year 1971, eight were installed in LT-1 ZR1 Corvettes. I believe the breakdown is 4 convertibles and 4 coupes. I know of at least 4 of these cars. The other 122 transmissions went into the LS-6 cars. Twelve went into the LS-6 ZR2 optioned cars, we now know of 7 of the 12. The other 110 transmissions are in regular LS6 Corvettes. This leaves 78 LS6 Corvettes that were either ordered with TH400 transmission or the M21 transmission. Currently we have 12 LS-6's built with automatics and another 12 built with M21 close ratio transmissions.
M22 transmission equiped LS-6's use the HD dual plate clutch set-ups as part of the package. M21 transmissioned cars have been seen with the standard 11 inch clutch.
Team Owner
Joined: Jul 1999
Posts: 26,545
Likes: 46
From: Huntersville NC
early shark, Are you saying that there were no M-22 transmissions installed with the regular LT-1 option? If I read you correctly you say that of 130 total M-22 transmissions 8 went into ZR1s, and 122 went into LS-6 bigblocks.
So, back to Jermo, does your 4 speed trans have your vin derivative stamped on it? And how do you know it's an M-22? Were they identified with a code in 72?
So, back to Jermo, does your 4 speed trans have your vin derivative stamped on it? And how do you know it's an M-22? Were they identified with a code in 72?
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Originally Posted by PRNDL
So, back to Jermo, does your 4 speed trans have your vin derivative stamped on it? And how do you know it's an M-22? Were they identified with a code in 72?
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Thread Starter
Racer
Joined: Aug 2003
Posts: 406
Likes: 68
From: San Clemente
Originally Posted by PRNDL
early shark, Are you saying that there were no M-22 transmissions installed with the regular LT-1 option? If I read you correctly you say that of 130 total M-22 transmissions 8 went into ZR1s, and 122 went into LS-6 bigblocks.
So, back to Jermo, does your 4 speed trans have your vin derivative stamped on it? And how do you know it's an M-22? Were they identified with a code in 72?
So, back to Jermo, does your 4 speed trans have your vin derivative stamped on it? And how do you know it's an M-22? Were they identified with a code in 72?
Thread Starter
Racer
Joined: Aug 2003
Posts: 406
Likes: 68
From: San Clemente
Originally Posted by FrankVincent
1971 production statistics from "Black Book":
total M22 = 130
total LT1 = 1,949 (350/330hp)
total LS6 = 188 (454/425hp)
total ZR1 = 8 (LT1 engine package includes M22)
total ZR2 = 12 (LS6 engine package includes M22)
Since the M22 was only available in the LT1 and the LS6,
I'd say you probably have a pretty rare option.
20 of the 130 went to ZR1 & ZR2 options.
so how many of the remaining 110 M22 went
to LS6 (188-12=176 left) and LT1(1,949-8=1,941) .... ??
Since those figures are not available,
I'd guess many of the LS6 cars had a M22, leaving only
a handful of LT1 cars with the M22.
You should also verify your car to see if it was a ZR1 ...
ZR1 included LT1, M22, TI, heavy brakes, Alum radiator,
metal shroud and special suspension.
(ZR1 did NOT have P/W, A/C, A/T, PO2, Alarm, radio)
nice car!!!
total M22 = 130
total LT1 = 1,949 (350/330hp)
total LS6 = 188 (454/425hp)
total ZR1 = 8 (LT1 engine package includes M22)
total ZR2 = 12 (LS6 engine package includes M22)
Since the M22 was only available in the LT1 and the LS6,
I'd say you probably have a pretty rare option.
20 of the 130 went to ZR1 & ZR2 options.
so how many of the remaining 110 M22 went
to LS6 (188-12=176 left) and LT1(1,949-8=1,941) .... ??
Since those figures are not available,
I'd guess many of the LS6 cars had a M22, leaving only
a handful of LT1 cars with the M22.
You should also verify your car to see if it was a ZR1 ...
ZR1 included LT1, M22, TI, heavy brakes, Alum radiator,
metal shroud and special suspension.
(ZR1 did NOT have P/W, A/C, A/T, PO2, Alarm, radio)
nice car!!!
Melting Slicks
Joined: Nov 2004
Posts: 2,672
Likes: 6
From: Nevada City California
Originally Posted by Jermo
I'll have to get back under the car when i get a chance to see the vin stamp, yes it's a M22, 1- I have the build sheet off the gas tank& last year I put a new clutch in her, i had a local speed shop that i trust replace it and they confermed it being a M22, the splines between the M21 & M22 are different
The front input splines are NOT different during the 1971 Muncie production year. M21 & M22 both have fine spline shafts. The helical cut gear teeth inside the main case are definitely different. M21 are approximately 40 degrees and M22 are 22 degrees (much straighter cut for durability and strength) hence they make the whining noise in the first 3 gears.
Could you post a picture of your Corvette Order Copy or email to me to view?
All factory data shows that no M22 option available to LT-1, other than mandatory on the 8 built LT-1 ZR1 cars.
Le Mans Master
Joined: Jan 2006
Posts: 8,319
Likes: 7
From: Wilmington DE, Drive it like you stole it, 68 327 4 speed coupe
Originally Posted by early shark
Jermo,
The front input splines are NOT different during the 1971 Muncie production year. M21 & M22 both have fine spline shafts. The helical cut gear teeth inside the main case are definitely different. M21 are approximately 40 degrees and M22 are 22 degrees (much straighter cut for durability and strength) hence they make the whining noise in the first 3 gears.
Could you post a picture of your Corvette Order Copy or email to me to view?
All factory data shows that no M22 option available to LT-1, other than mandatory on the 8 built LT-1 ZR1 cars.
The front input splines are NOT different during the 1971 Muncie production year. M21 & M22 both have fine spline shafts. The helical cut gear teeth inside the main case are definitely different. M21 are approximately 40 degrees and M22 are 22 degrees (much straighter cut for durability and strength) hence they make the whining noise in the first 3 gears.
Could you post a picture of your Corvette Order Copy or email to me to view?
All factory data shows that no M22 option available to LT-1, other than mandatory on the 8 built LT-1 ZR1 cars.
Melting Slicks
Joined: Nov 2004
Posts: 2,672
Likes: 6
From: Nevada City California
[QUOTE=PRNDL]early shark, Are you saying that there were no M-22 transmissions installed with the regular LT-1 option? If I read you correctly you say that of 130 total M-22 transmissions 8 went into ZR1s, and 122 went into LS-6 bigblocks.
PRNDL,
Yes, I have quite a bit of Chevrolet factory/dealership paperwork. I have never found any evidence that the M22 was an available option for the regular LT-1 Corvettes.
Along with the NCRS survey of 1971 LT-1's and my research on these cars through the years, none have ever surfaced with written documentation of such an occurrence.
However there are a couple of anomalies that we are researching currently, 1971 data shows that F41 suspension is available on different models for this year, however this is only available on the '70 & '72 LT-1 ZR1 cars in these years. Also data shows that the 1971 LS-6 cars came standard with the MA6 Heavy Duty dual plate clutch option with manual transmissioned ordered cars, however we have uncovered M21 cars, that this did not occur. All M22 cars have had this HD clutch.
PRNDL,
Yes, I have quite a bit of Chevrolet factory/dealership paperwork. I have never found any evidence that the M22 was an available option for the regular LT-1 Corvettes.
Along with the NCRS survey of 1971 LT-1's and my research on these cars through the years, none have ever surfaced with written documentation of such an occurrence.
However there are a couple of anomalies that we are researching currently, 1971 data shows that F41 suspension is available on different models for this year, however this is only available on the '70 & '72 LT-1 ZR1 cars in these years. Also data shows that the 1971 LS-6 cars came standard with the MA6 Heavy Duty dual plate clutch option with manual transmissioned ordered cars, however we have uncovered M21 cars, that this did not occur. All M22 cars have had this HD clutch.
Thread Starter
Racer
Joined: Aug 2003
Posts: 406
Likes: 68
From: San Clemente
Originally Posted by early shark
Jermo,
The front input splines are NOT different during the 1971 Muncie production year. M21 & M22 both have fine spline shafts. The helical cut gear teeth inside the main case are definitely different. M21 are approximately 40 degrees and M22 are 22 degrees (much straighter cut for durability and strength) hence they make the whining noise in the first 3 gears.
Could you post a picture of your Corvette Order Copy or email to me to view?
All factory data shows that no M22 option available to LT-1, other than mandatory on the 8 built LT-1 ZR1 cars.
The front input splines are NOT different during the 1971 Muncie production year. M21 & M22 both have fine spline shafts. The helical cut gear teeth inside the main case are definitely different. M21 are approximately 40 degrees and M22 are 22 degrees (much straighter cut for durability and strength) hence they make the whining noise in the first 3 gears.
Could you post a picture of your Corvette Order Copy or email to me to view?
All factory data shows that no M22 option available to LT-1, other than mandatory on the 8 built LT-1 ZR1 cars.
Melting Slicks
Joined: Nov 2004
Posts: 2,672
Likes: 6
From: Nevada City California
Originally Posted by Jermo
The order build sheet is too damaged to get a good picture of it and too faded . trans code is CC1 41229, I understand that the 1st C = M22 the 2nd C = March and the 1 = 1971
Jermo,
Understand completely about the Corvette Order Copy condition, they are a very fragile piece of paper and it is a carbon typed print that easily fades with harsh climatic conditions along with gasoline vapors. Unless removed early on or car is kept out of the elements, '71 & 72's tend to fade quicker than the '68 thru '70 sheets, as they are a different type of ink.
The stamping you state is not correct for St. Louis assembly plant. The stamping you should see would be in this format, ie: P1B12C. This stands for P - Muncie plant, 1 - year 1971, B - month February, 12 - twelve day of month, C - M22.
The ECL code under the option no. column on your Corvette Order Copy document should read something like this 1VM22AAV. This is from a 1970 LT-1 ZR1 coupe.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Originally Posted by early shark
Jermo,
The front input splines are NOT different during the 1971 Muncie production year. M21 & M22 both have fine spline shafts. The helical cut gear teeth inside the main case are definitely different. M21 are approximately 40 degrees and M22 are 22 degrees (much straighter cut for durability and strength) hence they make the whining noise in the first 3 gears.
Could you post a picture of your Corvette Order Copy or email to me to view?
All factory data shows that no M22 option available to LT-1, other than mandatory on the 8 built LT-1 ZR1 cars.
The front input splines are NOT different during the 1971 Muncie production year. M21 & M22 both have fine spline shafts. The helical cut gear teeth inside the main case are definitely different. M21 are approximately 40 degrees and M22 are 22 degrees (much straighter cut for durability and strength) hence they make the whining noise in the first 3 gears.
Could you post a picture of your Corvette Order Copy or email to me to view?
All factory data shows that no M22 option available to LT-1, other than mandatory on the 8 built LT-1 ZR1 cars.
Drive the car!--Big differance---1st-2nd-3rd sound like bad bearings-go into 4th sound goes away.
