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Hello Fellow Corvette Guys and Girls, A couple of things I need help with re my recently purchased 72 LT-1. Firstly do all these cars come standard with close ratio M21 4 speed or did you need to tick the box, if not did you get the standard M20 4 speed. Secondly did these cars come standard with Transitor ignition or again was this an option? Thank you in advance for your input, I dont know where else to turn to to get the info I need.
Congrats on getting such a fine Corvette!, it's a great car.
In 1972 you couldn't get a transistorized ignition on your LT-1, it wasn't available as a option.
However there was a special LT-1 option called a ZR1, not many made, you couldn't get a radio or power steering with it, maybe those had the transistor ignition, but I'm not positive about that.
Regarding the transmission choices, I believe it depended on which rear end gear ratio you selected( again, my memory is a little suspect, I'm sure someone will correct me if I'm wrong). Mine is a 3.70 rear end so I got the M21 close ratio.
There is something called The Corvette Black Book, and it's a handy reference, it will give you everything that came standard on your car, as well as, all the available options. You probably can find it on Amazon. Would love to see some pictures of your car sometime, due to some health issues, I haven't had mine on the road in some time, but I hope to remedy that this year.
Regards
Roy
One more thing, this forum is the best resource for finding out anything you need to know about your car, all you have to do is ask
Hi LR,
I believe Roy's thinking is correct.
Transistor ignition wasn't available for the 72 model year.
For the 70 model year it was part of the LT-! option but was also available as a stand alone option.
For the 71 model year it was part of the LT-! and LS6 engine packages only.
Regards,
Alan
Congrats on getting such a fine Corvette!, it's a great car.
In 1972 you couldn't get a transistorized ignition on your LT-1, it wasn't available as a option.
However there was a special LT-1 option called a ZR-1, not many made, you couldn't get a radio or power steering with it, maybe those had the transistor ignition, but I'm not positive about that.
Regarding the transmission choices, I believe it depended on which rear end gear ratio you selected( again, my memory is a little suspect, I'm sure someone will correct me if I'm wrong). Mine is a 3.70 rear end so I got the M21 close ratio.
There is something called The Corvette Black Book, and it's a handy reference, it will give you everything that came standard on your car, as well as, all the available options. You probably can find it on Amazon. Would love to see some pictures of your car sometime, due to some health issues, I haven't had mine on the road in some time, but I hope to remedy that this year.
Regards
Roy
One more thing, this forum is the best resource for finding out anything you need to know about your car, all you have to do is ask
Hello Roy, Thank you for your input, my car is 3.70 gears so it will have the close ratio box! How can you tell is there a stamp on the side of the box? I read somewhere that all LT-1 came with Transistorized ignition my car does not have so maybe you are correct Roy. I do have a black book 53-84 but there is very little about the LT-1. I hope you get yours up and running and thumbs up to better health. Cheers Roy thank you.
Hi LR,
"How can you tell is there a stamp on the side of the box?"
4-speed transmission cases have 2 stamps on them, both on the same flange on the case.
The first identifies the transmission source, when it was assembled, and whether it was wide or close range transmission
The second stamp was done at the assembly plant in St.Louis and is a partial VIN number that indicates what car the transmission was first installed in.
Regards,
Alan
The stamps are more difficult to see with the exhaust in place.
Hello Roy, Thank you for your input, my car is 3.70 gears so it will have the close ratio box! How can you tell is there a stamp on the side of the box? I read somewhere that all LT-1 came with Transistorized ignition my car does not have so maybe you are correct Roy. I do have a black book 53-84 but there is very little about the LT-1. I hope you get yours up and running and thumbs up to better health. Cheers Roy thank you.
Roy is correct. I also have a 72 LT-1 and it does not have TI, none of them did in 72. Mine also has the 3:70/M21 combination which is probably the most common setup that year.
Roy and Dan are correct that there was no T.I. standard on the LT-1 in 1972, nor was it available as an option.
What Gordonm says about the M21 on the optional rears make sense. You are right about the black book having little to say specifically about the LT-1, but look at the M21 as a no cost option and the optional rear axel. It kind of says that the optional rear gets you the M21.
Here's a picture of a M21 stamp. You will be able to see yours easily if you get under the car; best if on a lift. You may have to clean the grime. You see this stamp is P0A13B. P = Muncie, ) 0 = the model year, A = Jan., 13 = day of the month and B = M21. A is M20 and C would be M22 (ZR-1)
Roy, Dan and Gordon actually own LT-1s and their advice would be the most accurate.
Hi,
This is a 300 mile 1972 ZR-1.
It appears it has the standard BR-270 coil and doesn't have the T.I. harness running forward to a pulse amplifier.
I'm still thinking no T.I. was available for 72 production.
Regards,
Alan
I'm sure you are correct Alan, maybe I was thinking that the 20 or so ZR1 cars came with the M22 rock crusher transmission, I know there was something different about them from the regular LT-1 cars, but couldn't remember if it was the TI ignition, or the required transmission. If they didn't come with the TI ignition, I wonder why they required them all to be radio delete cars.
Regards
Roy
concerning the radio delete, if you look at the pictures, there is no radio shielding over the distributor or running down the sides, I'm assuming it wasnt removed.
Hi LR,
"How can you tell is there a stamp on the side of the box?"
4-speed transmission cases have 2 stamps on them, both on the same flange on the case.
The first identifies the transmission source, when it was assembled, and whether it was wide or close range transmission
The second stamp was done at the assembly plant in St.Louis and is a partial VIN number that indicates what car the transmission was first installed in.
Regards,
Alan
The stamps are more difficult to see with the exhaust in place.
Thank you Alan, That is a big help and will answer all my questions re the gearbox. I hope when I get under the car in about 2 hours time it is the numbers matching M21 box.
Much appreciated thank you.
Roy and Dan are correct that there was no T.I. standard on the LT-1 in 1972, nor was it available as an option.
What Gordonm says about the M21 on the optional rears make sense. You are right about the black book having little to say specifically about the LT-1, but look at the M21 as a no cost option and the optional rear axel. It kind of says that the optional rear gets you the M21.
Here's a picture of a M21 stamp. You will be able to see yours easily if you get under the car; best if on a lift. You may have to clean the grime. You see this stamp is P0A13B. P = Muncie, ) 0 = the model year, A = Jan., 13 = day of the month and B = M21. A is M20 and C would be M22 (ZR-1)
Roy, Dan and Gordon actually own LT-1s and their advice would be the most accurate.
Thank you Toylman, Very big help, what a wealth of knowledge you are, sure hope my box has a B on the end. Cheers.
Hi Dan, Thank you for that info, I have looked at the gearbox on my 72 LT-1 and it is a M20 box and I have 3.70 gears.
Were you able to determine if it was the original transmission? I haven’t seen that combination before but it certainly appears to have been available.
Were you able to determine if it was the original transmission? I haven’t that combination before but it certainly appears to have been available.
Thanks Dan, Yes it is the factory installed gearbox it has the last 5 digits of the vin number stamped under the box number, yea a little disappointing. I brought this vette from a guy in Vancouver and had it shipped to New Zealand it has only been in my possession for 4 days now . The car had a body off resto and the seller told me it had $40000 spent on it. Very smart car, Pewter silver with red interior, everywhere I look it shows like brand new, everywhere under side it shines new everything and it looks impressive. Engine is correct to the car, has P/S, P/B, P/W, Tilt/tele column, heated back window, and AM/FM Stero radio, 3 point seat belts, the red interior smells and looks brand new, its a beautifull car pitty about the gearbox. Thanks again Dan much appreciated your input.
Thanks Dan, Yes it is the factory installed gearbox it has the last 5 digits of the vin number stamped under the box number, yea a little disappointing. I brought this vette from a guy in Vancouver and had it shipped to New Zealand it has only been in my possession for 4 days now . The car had a body off resto and the seller told me it had $40000 spent on it. Very smart car, Pewter silver with red interior, everywhere I look it shows like brand new, everywhere under side it shines new everything and it looks impressive. Engine is correct to the car, has P/S, P/B, P/W, Tilt/tele column, heated back window, and AM/FM Stero radio, 3 point seat belts, the red interior smells and looks brand new, its a beautifull car pitty about the gearbox. Thanks again Dan much appreciated your input.
I remember this on was up for sale. Very nice car. It has a luggage rack, correct? Someday, tell us the story on how you purchased a car in Canada and have it shipped to New Zealand.
Hi LR,
It sounds like a VERY nice car from your description!
I really like the silver exterior with red interior combination.
I hope you get lots of pleasure from owning and driving it!
How about posting a few photos when you get a chance?
Good Luck!
Regards,
Alan
03-08-2018, 12:54 AM
72 lt-1
