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Good Big Block Heads?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Shawn, Apr 15, 2000.

  1. Shawn

    Shawn 1/2 ton status Premium Member Author

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    Looking to upgrade my 454 heads to something better. I currently have the truck (peanut) style which have the small ports and valves. I've been looking at these heads so far:

    Merlin
    Dart
    GM Performance

    I have to stay with oval ports. The valves will be a 2.19 and a 1.88. Any suggestions on these or other heads I should look at? One head shop was talking about selling me a set of stock 396 heads with larger 2.19 valves. This would result in more compression because of the smaller chamber according to them. Just looking for something to give a little more power but I'm not trying to build a 10 second drag Blazer.

    Hmmm... drag Blazer.... 2WD, tubbed, lowered, blown 502... if only the wife would let me...


    Shawn
    <font color=blue>87 K5</font color=blue>
    <font color=red>454, 6", D60, 14 blt, 465, 205</font color=red>
    www.off-road.com
     
  2. jmpd

    jmpd 1/2 ton status

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    What does the machine shop say they can do to improve your current heads? Can they port and mill the heads to get what you want? maybe they could offer a gasket thickness to help out on the compression side along with milling the heads. You sould be able ro get what you wnt out of your heads????Possibly,,,,

    The king head guy locally in AZ is Dean Turk I don't have the phone, but I know he is the guy around here. Maybe call and get a suggestion.

    Good luck
     
  3. shaggyk5

    shaggyk5 1/2 ton status

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    Just ask her real nice, shawn!

    shaggyk5

    aint nuthin in the world like a heavy chevy!!
     
  4. J.R.

    J.R. Guest

    shawn,what ever brand of heads you go with,you are going to spend big bucks.you might want to talk with a shop that only does head work to find how much power you are going to get for the dollar,i mean i figure that any upgrade that cost more than 10-15 dollars per horse power may not be worth it.i have seen people spend $1800 bucks just to get another 35-50hp. good luck,and i love to see other people put big blocks in there k5!!!!

    BIGBLOCK MAN
     
  5. mrprex

    mrprex Registered Member

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    Hey I want a 502!! Just to let you guys know, my birthday is coming up soon! hehe
     
  6. ken

    ken 1/2 ton status

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    The old closed-chamber 396 heads will up your compression about 1-1.5 points. I had these on my 454 and it had good power. I had to replace them cause we didn't put in the hard exhaust seats, and the unleaded fuel beat the seats out. So, if you use 396 heads, be sure to install the hard seats. Why would you want to waste your money on Merlins or Darts? A good set of properly set up 396 heads or "049" mid-70 454 oval ports are hard to beat. And, if you don't plan to turn over 5,000 rpms, the the small (2.06 & 1.72) valves are fine. The bigger (2.19) valves will "soggy up" your bottom end a bit. I guess it all depends on what you want to do with it, if you want to go duning, then max power/rpm is what you need, for instance. Good luck!

    ken
     
  7. Shawn

    Shawn 1/2 ton status Premium Member Author

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    Thanks for all the comments. I may just stick with the GM heads instead of Dart or Merlin. I found a set for $250 and I'll make sure to get the hardened seats.



    Shawn
    <font color=blue>87 K5</font color=blue>
    <font color=red>454, 6", D60, 14 blt, 465, 205</font color=red>
    www.off-road.com
     
  8. Captkaos

    Captkaos 1/2 ton status

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    You already know my opinion......

    For $250, you can't go that bad, especially if they are good. DEFINITELY go hardened seats. I would opt out of the larger valves for your application also. But....

    Chris Lucas
    http://www.wwisp.com/~captkaos
     
  9. CK5

    CK5 In my underwear Administrator Premium Member GMOTM Winner Author

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    Shawn, I almost forgot, check with "Heads by Paul" here in Denver, they do racing heads, the number should be in the phone book. These guys are very knowledgable and have been around forever.

    Steve
     
  10. Shawn

    Shawn 1/2 ton status Premium Member Author

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    I recently looked at my new Holley MPI manifold and noticed it has the smaller ports to match the truck style peanut port head. I called Holley on this and they said this was normal on all MPI oval port manifolds and it shouldn't make a difference (yeah right). Now I'm starting to wonder if larger oval ports heads will even help because of this. I could take the manifold somewhere and have it matched to the heads but I don't really want to spend the extra to do this.

    I'll also try Heads by Paul.

    Thanks for all the advice guys.


    Shawn
    <font color=blue>87 K5</font color=blue>
    <font color=red>454, 6", D60, 14 blt, 465, 205</font color=red>
    www.off-road.com
     
  11. ken

    ken 1/2 ton status

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    Well, if you look at Edelbrock Performer manifolds for BB Chevys, they have the ports small to match the peanut port heads. I ran this intake with the larger oval port 454 heads (049 castings), then 396 oval ports, and now I have a set of ported and polished late model (1989) peanut ports on my 454 and it has the most torque of all the head combos I've had. Seems to rev well up to 5,000 RPM, about where the Comp 260 cam and Edelbrock intake die off. The great part about it is the torque down low, it's got a mountain of it!!! I would seriously consider sticking to your peanut port heads if you don't plan to spend too much time above 4,000 RPM. Sure, they're not what "looks" powerful and armchair engine engineers will tell you the peanut ports are no good...but the above are my EXPERIENCES with all versions of heads on virtually the SAME 454 short block. Take it for what its worth. Good luck in your decision.

    ken
     
  12. Shawn

    Shawn 1/2 ton status Premium Member Author

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    Thanks for the response Ken. I may just stick with what I have. I just purchased TSM rear disks and another 205 so my funds are depleted for a while anyway... I'm not planning on going over 5k rpm and I have to admit the low RPM torque is nice on the trail. Funny, I have the exact cam you have (Comp 260).


    Shawn
    <font color=blue>87 K5</font color=blue>
    <font color=red>454, 6", D60, 14 blt, 465, 205</font color=red>
    www.off-road.com
     

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