1970 Camaro SS 350 400 turbo transmission

Discussion in 'Transmission & Driveline Topics' started by 70Camaro350ss, Dec 3, 2017.

  1. 70Camaro350ss

    70Camaro350ss New Member

    3
    0
    Dec 3, 2017
    I am trying to find out how rare a 400 turbo was factory on a 1970 Camaro SS. My window sticker says it came stock with a 400 turbo M40 option. I would appreciate any thoughts.

    Jeremy
     
  2. CamarosRus

    CamarosRus Veteran Member

    I'm "thinking" that the only 70' Camaro that could have had the M40/Turbo 400 option was
    the Z28 and the L-34 396/350HP (actually a 402)

    Now I'm reading the CAMARO WHITE Book and its lists the M40 option at 71,832 units
    and the M35 Powerglide at 19,520 units ????

    Guess I need to learn why the Turbo 350 isnt listed in 1970 as a transmission option

    I'm hoping now someone will explain all of this ...................
     
  3. Gary S

    Gary S Administrator Lifetime Gold Member

    20,681
    195
    Apr 14, 1999
    Bismarck, North Dakota
    I believe it is the old GM terminology thing. Just like the M20 could be either a Saginaw or a Muncie M20 depending on engine choice, the M40 turbohydramatic could be either a TH350 or a TH400 depending on engine choice. If you ordered a Z28 or SS396/350 with automatic tranny, your M40 was a TH400. With any of the other engines, your M40 would be a TH350. In similar fashion, if you ordered a Z28 or SS Camaro with M20, you got a M20 Muncie. If you ordered your Camaro with any of the other engines, and ordered M20, you got a Saginaw 4 speed.
    RPO numbers on build sheets don't always follow the identifying terminology used in other GM documentation.
    So, Jeremy, I suspect if you check your tranny and find the original VIN stamped on it, you might find it is really a TH350.
     
  4. 70Camaro350ss

    70Camaro350ss New Member

    3
    0
    Dec 3, 2017
    M38 is for a 350 Turbo and M40 is for a 400. I bought the car and it has a 400 in it. Original as far as the owner can tell me. I bought it from the original owner. So pretty sure it is original. Just weird that none of the other 70 Camaro i had, had one. thank for the information.

    Jeremy
     
  5. Gary S

    Gary S Administrator Lifetime Gold Member

    20,681
    195
    Apr 14, 1999
    Bismarck, North Dakota
    Have you actually looked at the tranny? Is it truly a TH400, and does it have the VIN of the car stamped on it? That would go a long way to answering your question.

    You can't always trust the paperwork because of GM's terminology. They didn't necessary use the M40 designation for only TH400 trannys. While they maybe listed it that way in one place doesn't mean that in another place it could be lumped together.
    If you look at the production numbers listed on this site, you see a big problem right away.
    http://www.nastyz28.com/camaro/camaro70.html#rpo
    On the production number list, you see that M40 supposedly went into 71,832 Camaros in 1970. Now, we know that isn't possible that all those cars got TH400 trannys because there were only 8733 Z28s made and only 1864 L34 SS396 cars. If all of those Z28 and SS396 cars got TH400 which we know didn't happen because many of them had Muncie 4 speeds, then there would still be 61,235 more Camaros in 1970 that got the TH400. That didn't happen.
    That list shows no production numbers for the M38 tranny and we know that isn't right either. So, I'm still guessing that the production lists lumped all the 3 speed automatics under M40. Your window sticker might list it the same way as the production lists.

    CHECK THE TRANNY and find out for sure.
     
  6. wnmech

    wnmech Veteran Member

    690
    29
    Jul 20, 2014
    grand prairie tx.
    Gary where is the VIN number located on the turbo 400 transmission? I believe mine is original to my 71 but can’t find the VIN number on the data plate
     

    Attached Files:

  7. Gary S

    Gary S Administrator Lifetime Gold Member

    20,681
    195
    Apr 14, 1999
    Bismarck, North Dakota
  8. wnmech

    wnmech Veteran Member

    690
    29
    Jul 20, 2014
    grand prairie tx.
    Gary
    Thanks I gots to get into the mood and jack it up and look.
     
  9. 70Camaro350ss

    70Camaro350ss New Member

    3
    0
    Dec 3, 2017
    The original transmission is not in it. I can't remember what it was when i removed it 7 years ago. I was a younger and dumber. I know the car has a 350 turbo cross member in it now and i have never changed it. The other transmission bell housing cracked. I know that when i put this one in i had to get a different shift cable mounting bracket because it had a 400 turbo bracket on it. but the cross member is wrong for that transmission. I guess you are right. it may just have referred to M40 as a turbo. It just weird that in 70 M38 was for a 350 and M40 was for a 400. I guess i will look for a 350 turbo from 70 and sell these two 400 I bought and set on the shelf. Not trying to argue, just want a 70 Camaro that was as close to original. Thank you for the insight. We may never have a 100% answer, but yours will do till i find in writing different. V/R Jeremy
     

Share This Page