71 LT1 with M22 Transmission

[Jerry Weidner]

Re: 71 LT1 with M22 Transmission

Here are 2 more pics, one of the emission label with the AX code indicating 71 LT1 and of the door sticker with the correct vin.

[Jerry Weidner]

Re: 71 LT1 with M22 Transmission

Here are 2 more pics, one of the emission label with the AX code indicating 71 LT1 and of the door sticker with the correct vin.

[Richard F.]

Re: 71 LT1 with M22 Transmission

Jerry, It doesn't by any chance have the 436 aluminum radiator or the J56 brakes, does it? Accidentally putting an M22 into an LT1 seems like too big of a mistake even for the GM production line. It's certainly interesting that the trans was noisy way back when. I sure hope you will let us know whatever you discover.

[Richard F.]

Re: 71 LT1 with M22 Transmission

Jerry, It doesn't by any chance have the 436 aluminum radiator or the J56 brakes, does it? Accidentally putting an M22 into an LT1 seems like too big of a mistake even for the GM production line. It's certainly interesting that the trans was noisy way back when. I sure hope you will let us know whatever you discover.

[Jerry Weidner]

Re: 71 LT1 with M22 Transmission

I haven't gotten that far yet in looking over the car, You could order the M22 as an option for an Lt1 couldn't you? I will let you know what I find as I go over the car.

Jerry

[Jerry Weidner]

Re: 71 LT1 with M22 Transmission

I haven't gotten that far yet in looking over the car, You could order the M22 as an option for an Lt1 couldn't you? I will let you know what I find as I go over the car.

Jerry

[Joe L.]

Re: 71 LT1 with M22 Transmission

Jerry-----

I think it's original, too. I believe that there have been heretofore documented cases of 1971 LT-1 with M-22 (other than ZR-1).

[Joe L.]

Re: 71 LT1 with M22 Transmission

Jerry-----

I think it's original, too. I believe that there have been heretofore documented cases of 1971 LT-1 with M-22 (other than ZR-1).

[Warren F.]

Re: 71 LT1 with M22 Transmission

Jerry,

I think where the confusion comes in, is in the 1971 Chevrolet Sales Album. Under the Corvette section on page 10 under the heading of Engines, Transmissions & Axle ratios it shows both the LS6 and LT-1 options as having available axle ratios under the spec close ratio column (which is the M22 trans). However on page 11 under the heading of Transmissions only the LS6 is listed as having the spec close ratio transmission available. The LT-1 is shown as having the wide ratio or close ratio trans available.

Also I have the 1971 Preliminary Corvette Order sheet, Rev. 4/70 which lists under Transmissions that the LS6 option is only available for M22, also under Engines the LT-1 option is listed with wide range or close ratio transmissions. The LS6 option is listed with close ratio, spec close ratio or TurboHydramatic transmission.

Also I have the 1971 Corvette Order sheet which is revised from the earlier document Rev. 7/70. This sheet lists spec 4spd Close Ratio w/425-HP engine. The LT-1 engine is listed under the ZW4 or M21 boxes as available.

There were 8 LT-1 ZR1's built and these all came with the racing HD components which included V01, F41, J56 & M22. I believe that page 10 of the Chevrolet Sales Album in listing the LT-1 option under the Power Train combinations in the HD transmission column, was referring to those LT-1's optioned out in ZR1 configuration.

[Warren F.]

Re: 71 LT1 with M22 Transmission

Jerry,

I think where the confusion comes in, is in the 1971 Chevrolet Sales Album. Under the Corvette section on page 10 under the heading of Engines, Transmissions & Axle ratios it shows both the LS6 and LT-1 options as having available axle ratios under the spec close ratio column (which is the M22 trans). However on page 11 under the heading of Transmissions only the LS6 is listed as having the spec close ratio transmission available. The LT-1 is shown as having the wide ratio or close ratio trans available.

Also I have the 1971 Preliminary Corvette Order sheet, Rev. 4/70 which lists under Transmissions that the LS6 option is only available for M22, also under Engines the LT-1 option is listed with wide range or close ratio transmissions. The LS6 option is listed with close ratio, spec close ratio or TurboHydramatic transmission.

Also I have the 1971 Corvette Order sheet which is revised from the earlier document Rev. 7/70. This sheet lists spec 4spd Close Ratio w/425-HP engine. The LT-1 engine is listed under the ZW4 or M21 boxes as available.

There were 8 LT-1 ZR1's built and these all came with the racing HD components which included V01, F41, J56 & M22. I believe that page 10 of the Chevrolet Sales Album in listing the LT-1 option under the Power Train combinations in the HD transmission column, was referring to those LT-1's optioned out in ZR1 configuration.

[Joe L.]

Re: 71 LT1 with M22 Transmission

Jerry-----

As far as I know, M-22 was not "officially" available with LT-1 (except ZR-1) for the 1971 model year. However, as I mentioned previously, I believe there have been other documented cases of this combination.

The really interesting thing would be what bellhousing (and, consequently, clutch) that this car has. The "CGZ" coded engine should have been supplied with a 14" flywheel, 11" clutch and GM #3988621 bellhousing.

"CGY" LT-1's included with the ZR-1 package had a 12-3/4" flywheel, 10-1/2" clutch, and GM #3858403 bellhousing.

[Joe L.]

Re: 71 LT1 with M22 Transmission

Jerry-----

As far as I know, M-22 was not "officially" available with LT-1 (except ZR-1) for the 1971 model year. However, as I mentioned previously, I believe there have been other documented cases of this combination.

The really interesting thing would be what bellhousing (and, consequently, clutch) that this car has. The "CGZ" coded engine should have been supplied with a 14" flywheel, 11" clutch and GM #3988621 bellhousing.

"CGY" LT-1's included with the ZR-1 package had a 12-3/4" flywheel, 10-1/2" clutch, and GM #3858403 bellhousing.

[Joe L.]

Correction

The bellhousing casting number in the second paragraph should be 3899621 and NOT 3988621.

[Joe L.]

Correction

The bellhousing casting number in the second paragraph should be 3899621 and NOT 3988621.

[Jerry Weidner]

Re: Correction

I will have a look at the bellhousing tommorrow as I have the car on a lift at work. Looking through some of the mechanical repairs that were documented I do not see where the bellhousing was ever changed. There is a repair that shows a heavy duty clutch was installed however. The engine was overhauled once and there are notes that say "the pink connectings rods were replaced with blue tip ones", Were the pink tip rods used for LT1's?
Also there is a letter from Guldstand Engineering inc in Culver City California informing the owner that they have discontinued there amplifier services and suggested replacing with an MSD 6-A unit. Looks like a pretty old form. John Costa was the service manager. There is alot of neat paperwork that was saved.

Is the rear end code correct: AC 7E2 I believe thats what it says.

Regards,

Jerry