Gen 3 hemi performance

New Hemi Engine Swaps

  1. 408 swinger

    408 swinger FABO Gold Member FABO Gold Member

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    Long time lurker, first time to post. I have a '74 Swinger, gen 3 426c.i.(hughes engines dyno test 21) 1000 cfm demon carb(81 primaries-91secondaries), timing at 20 degrees from 4000rpm on, 727 with cheetah trans brake and ati convertor built to match, Dana 60 4.10 gear spool. Ladder/leaf rear with anti-roll bar, Comp. Engineering shocks all four corners, rears set at 50/50 fronts 90/10, 30x9.50 hoosier radiual slicks. it sixty foots 1.38-1.40 pretty cosistently. Car with driver is 3250 lbs. I shift at 7000, and it traps about there, too. Best e.t. to date is 10.23 and best mph is 130. Density altitude is usually hovers around 3500 to 4000 in the heat of summer. Seeing some other builds on here and on moparts, it seems I'm a little off the pace. any suggestions appreciated. Thanks for reading through my rubble, Lol.
     
  2. mcat

    mcat Well-Known Member

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    i bet there is .3 in the altitude, have you tried different shift points? i wonder what a 6 or 6500 shift would bring..
     
  3. 408 swinger

    408 swinger FABO Gold Member FABO Gold Member

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    Something to think about. I figured the altitude was probably my biggest enemy. We don't get many "good air" days. Track elev. is 1350. We have test and tune at the end of the month. Good time to try the shift point deal. Thanks for the suggestion.
     
  4. mcat

    mcat Well-Known Member

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    i have a set number of difference on shift points.
    if my e.t doesnt change by that number, it is not worth the extra RPM abuse for me..
     
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