Headers

Discussion in 'Race 400/430/455' started by jmhock, Feb 3, 2021.

  1. hugger

    hugger Well-Known Member

    Its up to you obviously,..but high rpm and blower and N20 apps are usually where you see such size headers,..there are thousands upon thousands of 572~58x BBC's making BIG power and running well into the 8s with 2.125 primaries,...I just would hate to spend that kind of money on maybe 10hp MAYBE,..20hp for a small window in the curve. That money could be much better spent elsewhere,..jmo what did the heads flow at .700?
     
    70 GMuscle likes this.
  2. 70 GMuscle

    70 GMuscle Plan B

    Does TA make 2 1/8” for your car?
     
  3. 70 GMuscle

    70 GMuscle Plan B

    I go 9.50s w 2” hooker comp headers and 3” exhaust to rear. H pipe. 800 hp 555. Nothing crazy.
     
  4. BuickGSrules

    BuickGSrules Gold Level Contributor

    Then I have two very uniqe sets - a stage 1 and a stage 2 set both jet hot coated.
     
  5. jmhock

    jmhock Well-Known Member

    The heads flowed 291 at .700. I have 3" exhaust with X pipe, 2" primary with 3" collectors, Ceramic coated.
    TA makes larger 2 1/8 and 2 1/4 primary tubes but for 68 up and race frame cars.
    I am HAPPY to stay with the 2" if you RACERS believe that will work fine. I didn't notice anything negative with that setup before. Only adding another .020 to the bore. Should be 4.560 to 4.580. The piston pin clip broke and scared the cylinder on #6.
     
  6. standup 69

    standup 69 standup69

    If it was me I'd try just cutting and replacing the collector to 4 inch may be a happy medium at not an outrageous cost ..the bigger inches will like the bigger collector ...the 2 inch primary might be on the small side but the sp2 on the intake side is also too small IMO
     
  7. 12lives

    12lives You die once. You live every day.

    An old set of MT's fit - might make a good template?
     
  8. jmhock

    jmhock Well-Known Member

    Picts of SP2 porting, any better?
     

    Attached Files:

  9. hugger

    hugger Well-Known Member

    291??,...you sure?? Because TE heads flow more than that out of the box

    With what you have now,. The 2in headers are more than fine,...if you have the funds to spend you need headwork,...with 580in you need 360cfm minimum to even come remotely close to using those cubic inches.

    What did the engine make on the stand or better yet what did run?
     
  10. hugger

    hugger Well-Known Member

    That intake is pretty much untouched from what I see,...they rolled the short turn over in corners but honestly that clover leaf design isn't that great jmo
     
  11. jmhock

    jmhock Well-Known Member

    Not real sure on the flow, May be from the ported original ones.
    What intake do you suggest, direct FI?
    I will look for dyno sheet, around 800 if I remember correctly.
     
  12. jmhock

    jmhock Well-Known Member

    Back when it was 573. Demon carb, different cam, stainless valves, copper head gaskets and lots of H2O/oil mixing.
     

    Attached Files:

  13. hugger

    hugger Well-Known Member

    The sp2 is a capable intake,...but only after substantial work,...most everyone make over 750 goes to the SPX retrofitted for the TE heads or a Mopar intake to get the flow needed to support 800+hp,...what compression you running?
     
  14. jmhock

    jmhock Well-Known Member

    Around 11:1
     
  15. jmhock

    jmhock Well-Known Member

    Found the flow sheet. The 291 is exhaust and intake 369 at .650
     
    johnriv67 likes this.
  16. Chi-Town67

    Chi-Town67 Gold Level Contributor

  17. hugger

    hugger Well-Known Member

    A set of the 2.125 super comps are all you need,...if you had more comp and more intake I would say MAYBE,.. you would see a worthwhile gain with 2.250,...put some nice merge collectors on the TA super comps and you'll see a nice gain,..for around $2k time they are coated and everything,...you will need to do some frame clearance work and I would put a motor plate in it if it were me that free up alot of room down there
     
  18. johnriv67

    johnriv67 Well-Known Member

    That is the weirdest dyno chart I've seen. Look at the massive fluctuations in horsepower between each 100 rpm increment.
     
  19. hugger

    hugger Well-Known Member

    Probably a land and sea dyno

    Jim Burek had one that come over with Noah i think,..it was the same way huge fluctuations and pretty liberal too
     
  20. jmhock

    jmhock Well-Known Member

    That is were I started!
     

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