How Much Power Loss???

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  • 85maro
    • Sep 2006
    • 140

    #1

    How Much Power Loss???

    I have a pair of lightly ported '769 heads on my car now with 3500 valves installed. How much power am I missing out on vs the '487 heads I have? It's peppy the way it is now but I don't think it's all it should be. See my sig for the mods.
    Increasingly I find the difference between a "fact" and an opinion is the number of people who believe it.

    3.4 block converted to roller valvetrain with 220/225 cam on 115 lsa, '769' heads with 3500 valves, LS6 springs & porting, twin T04E turbos, 3500 plenum with ported 3400 lower & 'short star' 65mm throttle.
  • 85maro
    • Sep 2006
    • 140

    #2
    Anyone? I have it apart right now and want to make a decision.
    Increasingly I find the difference between a "fact" and an opinion is the number of people who believe it.

    3.4 block converted to roller valvetrain with 220/225 cam on 115 lsa, '769' heads with 3500 valves, LS6 springs & porting, twin T04E turbos, 3500 plenum with ported 3400 lower & 'short star' 65mm throttle.

    Comment

    • SappySE107
      WOT-Tech
      • Oct 2003
      • 13496

      #3
      I won't bother with 769 heads. The latest castings were much more consistent and flowed better stock vs stock.
      Ben
      60DegreeV6.com
      WOT-Tech.com

      Comment

      • 85maro
        • Sep 2006
        • 140

        #4
        I was searching for some flow numbers but couldn't find any. You think they're atleast on par with the later heads after a little work? I measured the ports on both and it looks like a .01" difference in port height otherwise they look pretty much the same.
        Increasingly I find the difference between a "fact" and an opinion is the number of people who believe it.

        3.4 block converted to roller valvetrain with 220/225 cam on 115 lsa, '769' heads with 3500 valves, LS6 springs & porting, twin T04E turbos, 3500 plenum with ported 3400 lower & 'short star' 65mm throttle.

        Comment

        • 85maro
          • Sep 2006
          • 140

          #5
          NM, found some numbers. About 10 cfm difference stock to stock.
          Increasingly I find the difference between a "fact" and an opinion is the number of people who believe it.

          3.4 block converted to roller valvetrain with 220/225 cam on 115 lsa, '769' heads with 3500 valves, LS6 springs & porting, twin T04E turbos, 3500 plenum with ported 3400 lower & 'short star' 65mm throttle.

          Comment

          • 2.8-350TBI
            RWD FTW!!!
            • Sep 2009
            • 350

            #6
            If you dont mind me asking, what are "769" and "487" heads?
            Originally posted by Mars
            Haha ^ Wrong Wheel Drive.
            S10 Blazer 4.3, turbo LX9 in its future...
            No 60šV6 at the moment

            Comment

            • 85maro
              • Sep 2006
              • 140

              #7
              Different castings. '769 is older and '487 is newer.
              Increasingly I find the difference between a "fact" and an opinion is the number of people who believe it.

              3.4 block converted to roller valvetrain with 220/225 cam on 115 lsa, '769' heads with 3500 valves, LS6 springs & porting, twin T04E turbos, 3500 plenum with ported 3400 lower & 'short star' 65mm throttle.

              Comment

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