455 Engine Questions - Recommedations

Discussion in 'Street/strip 400/430/455' started by Utah455, Feb 24, 2019.

  1. Utah455

    Utah455 Platinum Level Contributor

    I have a 70GS but found out the motor is actual from a 1976 (possibly a Regal) 455. All I want to do is clean and freshen the motor. i.e. degrease, paint and just change the valve cover and oil pan gaskets. New starter and sending units. The motor ran when I pulled it out of the car a few years ago. It was rebuilt (apparently) by previous owner but don’t know what was done. That was 20 years and only 2000 miles ago. Deck is milled, so no numbers. Degreasing showed the 76Date code and Vin on the front.

    Now to the questions. Someone mentioned to replace the intake manifold with a 70 intake due to the emissions regulations. I do have a junk yard 455 from a 70 Lasabre or Electra (can’t remember) but it’s pretty dirty. Would the 70 intake manifold bolt straight up to a 76 block? Any modifications needed? What year gasket do I buy?

    I’ve purchased a gasket set for a 70 455 block a while back, would any of those gaskets fit the 76? Would the oil pan and valve cover gaskets from the 70 match up? Any recommendations to pick up a 455 gasket set for a 1976?

    Thanks in advance for your help!
     
  2. hugger

    hugger Well-Known Member

    You need to ditch the 76 heads and get some pre 72 heads and then you can run the early manifold or you will have to block the heat riser ports, but the 75/76 heads are junk
     
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  3. Philip66

    Philip66 Well-Known Member

    Oil pan and valve cover gaskets are the same thru all years.
    Water pump should be same as well as timing cover too.

    If you have a complete 70 motor you could take the 70 heads and get them freshened.

    If you already have the motor out it's not hard to switch heads now before you put it back in.
    You'll be miles ahead...
     
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  4. 70 GMuscle

    70 GMuscle Plan B

    Put the 70 top end on
    Heads and intake.
    Best bang for buck
    Easy to do with engine out.
    Send the heads for a valve job.
    You can’t go wrong and it will set you up for future upgrades.
     
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  5. Utah455

    Utah455 Platinum Level Contributor

    7768CC0E-9A05-45B5-9BCC-4CEAA4A19385.jpeg 978AE1BB-BAC3-4613-9813-2AE4FC56E1B4.jpeg BF29FB50-C2F9-4593-A295-16FB7AE0E6D3.jpeg 2934259A-FA06-4A8B-A22F-5003F767768D.jpeg Upon further inspection, I noticed my heads do have a 72 on them and the intake manifold has a number of 1239925 which appears to be a 72 intake manifold. What I think is the old EGR port has a plate cover on it. So I may be better than I thought. Funny thing is the block has the 1241735 casting number which I thought was 72-75 but the front serial number is 46Hxxxxxx
     
  6. 1969RIVI

    1969RIVI Well-Known Member

    Chances are you got a 72 455 complete engine, which isn't that bad. That's what I'm running right now while I'm building my 70 455. Like others said put your 70 top end on it and go! OR if it's still running good put it back in and run it for a bit and take your time building up your 70 from the lesaber.
     
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  7. Utah455

    Utah455 Platinum Level Contributor

    Thanks for all the info. Yeah, it was running good when I pulled it. Thinking just a fresh coat of paint and the easy gaskets. New starter, sending units and definitely new wire harness. Once back on the road, we’ll see about a full rebuild on the 70 motor.
     
  8. 1969RIVI

    1969RIVI Well-Known Member

    Here's a chart for referencing casting numbers
     

    Attached Files:

  9. 69GS400s

    69GS400s ...my own amusement ride!

    Change the timing gear and chain
     
  10. Philip66

    Philip66 Well-Known Member

    X2

    Absolutely!!
    Pull the balancer off; get the timing cover off; plan on replacing timing chain & gears. Sure, you could get in there and see that there's a new double roller in there, but not likely. Wouldn't want to trust your engine to those brittle factory timing gear teeth!
     
  11. johnriv67

    johnriv67 Well-Known Member

    FF1B4523-A280-4E23-BAA3-41AB3BEB796B.jpeg This top chain and gear is off of my 67 430 with 85k miles. There are literally no plastic teeth left. New piece is in the middle and the bottom one was off a 68 430 that was also an aftermarket replacement
     
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  12. 70 GMuscle

    70 GMuscle Plan B

    When using a double roller w a stock type fuel pump you must elongate the mounting bolt holes in the fuel pump to space it forward away from the chain.-
    I learned the hard way. Ruined a new stage 1 pump in a few miles.
    Using RobbMc now w holes elongated by him and upon inspecting found no problem now.
     
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