How to identify a Pontiac 455

Discussion in 'The "Other" Bench' started by buickjunkie, Oct 26, 2006.

  1. buickjunkie

    buickjunkie Well-Known Member

    Hi,
    I'm going to look at a motor tonight for a friend, the seller says it's a Buick 455 out of a Firebird. The seller says the distributor is at the back and the oil filter is angled like a Buick at the front passenger side. We think it's going to be a Olds 403 but don't know how to identify it. :Do No:
    Thanks Bruce
     
  2. BlackGold

    BlackGold Well-Known Member

    If the oil filter is up front, it ain't no Olds.
     
  3. Keith Seymore

    Keith Seymore Well-Known Member

    Here are some notes for a Pontiac 455, in this case a 1971 block. Some of these items you wouldn't be able to see unless it is disassembled a bit (obviously):

    Bore: 4.150" (standard bore)
    Main bearing dia: 3.25"
    Main bearing bolts: 2 bolt main
    Freeze plugs: three per side
    Motor mount bolt locations: five per side
    2 digit year code near distributor: yes "71"
    Displacement cast on side of block: yes, "455"
    Displacement cast into lifter bore: yes "5 5"
    Transfer lug at rear of block (pyramid): yes
    Date code: A061
     
  4. cstanley-gs

    cstanley-gs Silver Mist

    for a Pontiac 455, I believe the starter will be on the drivers side.
    and distributor will be at the rear.
    oil filter is at the passenger side rear, almost straight down

    There are some pictures in this ebay auction that might help you compare
    http://cgi.ebay.com/ebaymotors/Pontiac-455-stroker-motor_W0QQcmdZViewItemQQcategoryZ33615QQihZ016QQitemZ260005775119

    I googled "Pontiac 455", then clicked the images link at the top and you will find many images of a 455.

    [​IMG]

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    [​IMG]

    There is even a video on this page of a Pontiac 455
    http://chevystreetperformance.com/video_gallery.htm
     
  5. online170

    online170 Well-Known Member

    A couple of quick checks. If its an olds rocket motor, it will have 10 bolts for the valve covers. Not sure about pontiac but from above pix it looks like it only has 4. Another quick check, take a peak at the distributor. It should be behind the intake, i think this is true for both olds and pontiac though. Thats about all i can think of.
     
  6. pegleg

    pegleg Well-Known Member

    Pontiac

    ALL pontiacs, real ones, have a seperate valley cover. Olds motors have the valley cover cast into the intake. If you can get to the crank, the big pontiacs, 421,428 and 455 have a 3.25" main. None of the smaller motors do.
    :TU:
     
  7. slowride66

    slowride66 "TAKE IT EASY"

    On Pontiac the older ones on the Drivers side front of the block will be raise in big numbers 350 or 400 or 455.

    Hard to see in the car but try a mirror & a flashlight.


    SR66 :TU:
     
  8. buickjunkie

    buickjunkie Well-Known Member

    Hi,

    Thanks for all the replys. The owner / seller was a bit off in his description, the distributor is at the front on an angle, it did come out of a 74 or 75 Firebird, must of been a real screemer. It's a Buick 455 red block , no egr, no air pump, casting # 1238861, which puts it at 1971 or 1972, with a long shaft th400. He said it was last run a year ago, missing the breather and fan.
    No Idea of milage. The owner says it's a 360 HP (Stage 1 ?) anyway to varify this without pulling the heads
    Thanks Bruce
     
    Last edited: Oct 27, 2006
  9. bob k. mando

    bob k. mando Guest

    the two digit block code ... assuming nothings been swapped or screwed with.

    http://www.buicks.net/shop/reference/engine_ident_63_75.html

    http://www.buicks.net/shop/reference/engine_ident_where.html

    only the 1970 'SS' code engine is '360' hp. 71 saw a large decrease in compression and the top rating was 345hp on the 'TS' stage 1 engine. 72 was the conversion from gross to SAE net ratings and the 'WS' engine, which is almost identical to the 'TS' engine, was derated to 270hp.

    the 71-76 engines can, in a practical way, be converted to '1970 Stage 1' status by swapping in 1970 heads (pull the valve covers and you can see the casting number) and pistons.
     
  10. buickjunkie

    buickjunkie Well-Known Member

    Hi,
    Thanks for the reply.
    I'm all over this like a wet mop.
    I'm trying to find where to de-code engine numbers other than Stage 1
    The block currently in my garage looks like a TR code, casting #1231788
    The one in I looked at last night the casting number is a 1238861, which could be a Stage 1, could this also be a stock GS motor.
    In which Buicks was the Stage 1 option offered, eg GS, Riv. Centurion etc ?
    I'm going to have to go back and get the engine serial #, carb # and distributor #.
    Thanks Bruce
     
  11. Floydsbuick

    Floydsbuick Well-Known Member

    Easy way to tell a Pontiac? The pass side cylinder bank is further ahead than the driver side. Thus number one is pass side front. The Buick, Olds, and Chevy have the driver side cylinder bank further ahead and number one on the driver side.
     
  12. bob k. mando

    bob k. mando Guest

    The one in I looked at last night the casting number is a 1238861, which could be a Stage 1, could this also be a stock GS motor.

    the head casting number has NOTHING to do with whether or not the engine is stage or not.

    Stage heads were pulled out of the standard stampings in the normal production line and the engineers overbored the large Stage valves by hand. you can only verify Stage heads by pulling the head and checking actual valve sizes. it's entirely possible (though very unlikely) to have a Stage block code stamping that has had non-Stage heads swapped onto the motor ... and still have the correct casting numbers.
     

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