oldsmobile engine id

Discussion in 'The "Other" Bench' started by tt455, Nov 16, 2019.

  1. tt455

    tt455 T Bone

    Can anybody tell just by these 2 photos if this is a 455 olds engine. Looks wide enough, was told it was I don't have access to it. Not sure of the year either the person can not find any numbers. The alternator is usually on the other side on 442 cars maybe altered or a later big car engine? olds455a.jpg olds455.jpg
  2. mrolds69

    mrolds69 "The Cure"

    At the front of the engine where the oil filler tube is there is a big cast letter and a casting number on the engine. Like an F is a 455, a G is a 400, etc. It does not look wide enough for a 455 to my eye.
  3. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    Even if it was wide enough it could still be a 400 or a 425.
    mrolds69 likes this.
  4. mrolds69

    mrolds69 "The Cure"

    Sure, that's true, that's the thing that makes Olds engines hard to ID. Even the smaller engines look big because 330-455 all take the same valve covers, I think.
  5. Demolition man

    Demolition man Well-Known Member

    image.jpeg A quick way to ID a 455 is look for the cast renforcment thin line, that this stick is pointing at in pic.
    Cast line is 455 , No cast line = something else
  6. Demolition man

    Demolition man Well-Known Member

    It appears to me that your motor has that cast line and is a 455! Also under one of one of the exhaust manifolds will be a CID cast.
  7. Brandon Cocola

    Brandon Cocola Well-Known Member

    The letter on the head above the exhaust manifold is the best way to id the engine. If they take a picture of the passenger side you should be able to see it.
  8. Brandon Cocola

    Brandon Cocola Well-Known Member

    Another thing is a small block will have a 12in wide intake and the big block will be 14 that will only narrow it to 400, 425 or 455. Heads will only help if they haven't been changed.
  9. tt455

    tt455 T Bone

    Thanks for all the great info guys. I asked him to check but he's not near the car. I tried to do some research before posting but as stated they are hard to identify.
  10. Demolition man

    Demolition man Well-Known Member

    image.jpeg Here is a pic of a known 350 olds in my backyard. Note the lack of the casting thin line behind water pump.
    I am uncertain if these are on 400 or 425 but positive that are on 455s and not on 350s on down
  11. telriv

    telriv Well-Known Member

    ONLY 455's have the casting line.
  12. 1972Mach1

    1972Mach1 Just some guy.....

    Head casting letters on heads will only get you a ballpark. Olds heads are interchangeable between small and big blocks, as well, so as you said the valve covers offer no clue. Remember, "J" heads = Junk. "C" heads used to be what we looked for when I was into Olds's as far as good fairly common stuff. Small block heads have a number for a casting indicator instead of a letter, and I can't think of any reason someone would put small block heads on a big block, so that'd be another indicator if you spot an Olds out in the wild.
    Last edited: Nov 18, 2019
  13. Rocket Racer

    Rocket Racer Well-Known Member

    That only pertains to later model engines.
    A 455 will have a casting # of 396521 F in raised numbers behind the front cover, as well as a ~ 1" step up to where the intake seals.
  14. tt455

    tt455 T Bone

    So here is what I have, casting # 396021 F. I do not see a 2 letter code on the oil filler tube. On the heads is the letter G and I see 409 100. From what I can gather may be a 1971 455.
    olds455id.jpg olds455idb.jpg olds455ida.jpg
  15. Kennybill

    Kennybill Well-Known Member

    Yes, I vote for a 1971 455, G-heads. Ga heads came late 1971 and 1972. In 1973 on were J's.

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