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new heads or new motor?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by blazinbm, Jun 15, 2004.

  1. blazinbm

    blazinbm Newbie

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    my engine (5.7l 350) has 146,000 miles on it, it blows out smoke when I first start it up, so I was wondering should I get my heads rebuilt or just fork over the money for a stroker.
     
  2. Muddytazz

    Muddytazz 1 ton status

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    [ QUOTE ]
    it blows out smoke when I first start it up

    [/ QUOTE ]
    That is just a valve seat/seal problem.
     
  3. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    It all depends on what you want. If you are looking for more power than stock and really want to invest the time and money then go for it. Also make sure your pockets are deep enough before you start.
     
  4. crazy427

    crazy427 1/2 ton status

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    I have the same perdicament.My rig has 187,000 on the original bottom end. i put a set of replacement stock heads, a performance cam and new timing chain on it about 8 months ago. Everything was all good till about 2 weeks ago. I lost a cylinder.i did a leak down test and im getting 90 % leakage through the intake valve.so now i a stuck with the same problem . do the heads again on a bottom end with so many miles or just drop in the stroker? I opted for the stroker. 383 tbi engine with 350hp and 440 torque /forums/images/graemlins/usaflag.gif /forums/images/graemlins/k5.gif
     
  5. 4xcrazy

    4xcrazy 3/4 ton status

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    215k miles, and same smokin problem, but here recently with the outside temps rising, i am starting to get some valve rattle under acceleration or when the AC is being used, i personally am just going to wait to rebuild the whole motor as with the mileage where it's at, i'd hate to install new heads, then have the bottom end drop dead on me from the extra compression.

    I would just rebuild it.
     
  6. 84_Chevy_K10

    84_Chevy_K10 Banned

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    If you're not looking for a high performance engine I'd just get yourself a crate motor.
     
  7. 4xcrazy

    4xcrazy 3/4 ton status

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    Probably be cheaper,,,, /forums/images/graemlins/thinking.gif

    with less work,,,, /forums/images/graemlins/thinking.gif /forums/images/graemlins/thinking.gif /forums/images/graemlins/thinking.gif
     
  8. spoolnaround

    spoolnaround 1/2 ton status

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  9. xdelirious45x

    xdelirious45x Registered Member

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    Just recently replaced my heads, i rebuilt used heads with new valves, springs, seats, seals, o-rings, gaskets, rocker arms, pushrods, and everything has been running fine for me for about 4 weeks.
    If the motor is real old, i would think about getting a crate motor.... To check if this motor is real old, check all the manifold bolts, nuts, etc. When I was putting on the rebuilt heads, a few exhaust manifold bolts got stuck in the new heads, b/c i tried reusing them /forums/images/graemlins/doah.gif
    So, I would double check if you want to put new heads in, it would be cheaper, and it should solve your (blue=oil) smoke problem.
     
  10. kw48653

    kw48653 Registered Member

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    xdelirious45x, is it bad to re-use the manifold bolts?
     
  11. xdelirious45x

    xdelirious45x Registered Member

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    im not saying its bad, but if u replace heads, you must be extra careful not to strip, or crossthread manifold bolts, b/c if u do, you could destroy an entire job. /forums/images/graemlins/hack.gif /forums/images/graemlins/grind.gif /forums/images/graemlins/weld.gif
    I'm just giving advice from experience, b/c im not careful with anything i do, and i'm real clumsy.
     
  12. cybrfire

    cybrfire 1 ton status Vendor GMOTM Winner

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    I've had mixed results using rebuilt heads on a used bottom end. Seems like sometimes you still get blow by and smoke so I'd say if you have the cash get the crate motor as well.
     

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