72 skylark w/71’ 455

Discussion in 'Wet behind the ears??' started by Ryanjbill15, Nov 8, 2019.

  1. Ryanjbill15

    Ryanjbill15 Well-Known Member

    Good day,
    Question to all you experts out there. My 72 skylark as a 71’ 455 stage 1 transplant or so I’m told it’s a stage 1.

    I’ve done a good deal of exhaust work among other things over the past two years. I’m just not getting the sound I want. It continues to feel as if it’s just a lot of wishing sound, no purr, more like humming as I accelerate or decelerate. Anyways, how do I confirm the block year, if I hve stage 1 heads. Wondering if I got duped and it’s a mid 70’s low compression motor. From everything I’ve researched to reading about all your cars, it’s just feeling as if this motor isn’t that powerful and living up to the 360 hp, 500lbs torque

    current set up

    2.5 dual, stock manifolds, dynomax welded muffs.

  2. flynbuick

    flynbuick Super Moderator Staff Member

    Start by using a flashlight to look between the firewall and the back of the intake manifold. Facing up are the numerals 455 and a series of other numbers. What are those others numbers?

    Look for two letters stamped on either side of the hole for the oil dipstick. What are those letters?

    You will need to remove the heads to verify stage 1 size valves are present.

    Recurve the distributor and shed the 2.56 gears for increased performance.
  3. sriley531

    sriley531 Buckle up, this could get rough....

  4. Ryanjbill15

    Ryanjbill15 Well-Known Member

    Thank you, last year I did put in a Yukon gear set with Eaton posi. 3.23 gears.

    I’ll go grab the numbers and report back
  5. Ryanjbill15

    Ryanjbill15 Well-Known Member

    I couldn’t get to the oil dipstick side.

    but the code on the back of the block is

  6. UticaGeoff

    UticaGeoff Well-Known Member

    # show a 71-72 casting:

    Block Cast # Year Displacement
    1231738 70-71 455
    1238861 71-72 455
    1241735 72-75 455
    1242694 ?-? 455
  7. flynbuick

    flynbuick Super Moderator Staff Member

    Clean the flat surface area around the oil dipstick hole. Pull the dipstick and shine a light on that flat surface. Take a picture of that surface and post it here.
  8. johnriv67

    johnriv67 Well-Known Member

    Your exhaust setup sounds a lot like mine, except I have a 430. I have the dynomax ultraflows 2.5”

    sriley531 likes this.
  9. bigtorque5

    bigtorque5 Well-Known Member

    861 is the best stock eng,has the big oil pickup and livable compression
  10. Ryanjbill15

    Ryanjbill15 Well-Known Member

    Great, looks like the prior owner planed the deck so I’m not seeing any codes next to the dipstick indicating if a stage 1 or not.

    whats the HP difference between regular and a stage 1? Is it significant? If it is perhaps I look at a new set of heads?

    when you guys rev your cars does it rev and drop quickly or idle down slowly, mine seems to idle down very slowly compared to most high power applications.
  11. flynbuick

    flynbuick Super Moderator Staff Member

    16 horsepower per the factory powertrain engineer.
  12. flynbuick

    flynbuick Super Moderator Staff Member

    It is not definitive but you could get the numbers off the distributor and the carburetor to see if they are stage 1 units.
  13. Ryanjbill15

    Ryanjbill15 Well-Known Member

    Here’s the description the car had when I bought it two years ago. I’ve put in 3.23 posi since then. It also has a mild pro comp cam the prior owner put in vs TA 212.

    rebuilt 1971 model 455 stage 1 has around 4000 miles since rebuild with all new internals, 325 h, 520 lb-ft torque, block was drilled to improve main oiling, new 800 CFM quadrajet carberato, petronix ignition upgrades, new water pum, new fuel pum, new dynomax (I replaced with ultra flo) complete 2.5 inch dual exhaust, new heavy duty aluminum radiator, rebuilt 400 turbo, heavy duty clutches, and a shift kit was rebuilt with engine, all new polyurethane suspension bushings, new ball joint, all new steerin, quick ratio steering box,all new brake system front to back including e- brake cables, front disc rear drum power brakes fuel tank cleaned & coated with POR 15, heavy duty sway bar with all new bushings, new cooper cobra radial tire, new autometer gauges ( trans temp. engine temp, oil press. voltage), sunpro tach, 2.56 rear gear ratio with locked rear diff, 1.5 lowering sport spring, new engine wiring harness

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