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Big Block Heads

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

  1. Bigd

    Bigd 1/2 ton status

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    Would like too know if anyone has a list of the head casting numbers and the Cumbustion chamber cc's for each casting number.Going too rebuild a bb want too figure out what head and piston combo i need too get the comp ratio I want.
     
  2. Shawn

    Shawn 1/2 ton status Premium Member Author

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    Try these pages:

    http://www.nastyz28.com/bbcmenu.html

    http://roadsters.com/bbc.html

    I just picked up a set of GM 353049 heads which are pretty decent and I'm having 2.19 valves and SS seats installed. To match the oval ports I have to port my Holley MPI manifold since it's closer to a peanut port style.

    Shawn
    87 K5 454
     
  3. Bigd

    Bigd 1/2 ton status

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    Thanks thats exactly what i was looking for.I think i'm going too do a fairly stock rebuild.Just a mild cam and maybe headers.I just want the torque.By the way those spacers worked perfect i like them.I just got done changing the window frame.I kind of messed up i was in such a hurry i should have took a butt load of pictures and submitted a article.
     
  4. ken

    ken 1/2 ton status

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    The 049 and 781 heads are great. But do not discount the "peanut" port heads. I had to replace the 049s on my 454 (valves burnt) and installed a set of 1989 "peanut" port heads (don't remember the casting #), fully ported and polished them...and they work FANTASTIC. She'll rev up to 5 grand with ease, and I mean, how much more do you need to twist a BB?!?!?! Oh, BTW, it has a Competition Cams 260 duration cam, headers, Edelbrock intake and carb and is balanced. Seems like the power is the same, only more of it down low!!!

    ken
     
  5. Captkaos

    Captkaos 1/2 ton status

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    This is just a side note but to answer your comment "how much more do you need to twist a BB?!?!?"
    How about 8200rpms?


    Chris Lucas
    http://www.wwisp.com/~captkaos
     
  6. Shawn

    Shawn 1/2 ton status Premium Member Author

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    Did you use SS valves and seats on those 049 heads? Since I'm at 5800ft (Mile High Denver) air is scarce thus the reason I'm having larger valves installed in the 049 heads. Up here we need more air and less fuel. Don't get me wrong, the peanut port style heads are a good head for torque but I've also tried both of these heads and without head mods, the 049 heads seemed much stronger. The 049 heads are off of my third engine which lost the mains. The 4th motor is a GM crate that came with the peanuts.

    We think too much a like Ken! Same axles, shocks, engines, brakes, etc...

    Shawn
    87 K5
     
  7. ken

    ken 1/2 ton status

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    That's the last thing I need is a BB that'll twist 8200 RPMs...well maybe a pair for my barge...but when towing, 8200 RPMs is pretty useless. I moreso need the torque/grunt to drag that barge up these grades in CA (Baker and Cajon) on the way to Mead and Powell.

    And yeah, Shawn, I would never have run the peanuts without porting and polishing them. They now exceed the old 049s.

    ken
     
  8. Shawn

    Shawn 1/2 ton status Premium Member Author

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    The main reason I'm replacing the peanut port heads is the Edelbrock intake and heads don't exactly match. A few head shops have told me this creates a turbulance above 2000 rpms. The real kicker is I get the 049 heads and it turns out the Holley MPI manifold (supposely oval ports) doesn't match either. The MPI manifold is a cross between a oval port and a peanut port so now I'm having that ported to match the 049 heads. It's never easy!

    Shawn
    87 K5
     
  9. ken

    ken 1/2 ton status

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    Yeah, that's the bit*h about Edelbrock intakes...they are a cross between peanut and oval, not quite right for either. Next BB intake I buy will be a Weiand, they have the correct oval ports...not a compromise.

    ken
     

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