B4b or sp1 ??

Discussion in 'Street/strip 400/430/455' started by steve murray, Aug 13, 2021.

  1. steve murray

    steve murray Well-Known Member

    So I know this has been discussed before , and prob at length ! I’d like some honest input from those who know and have thrashed both ! Fresh 455 almost ready to pick up from builder. It’s .040 over , true 10:1 Comp cam .499 lift maybe 236/238 duration 113,lobe sep. I DONT HAVE CARD IN FRONT OF ME, but healthy street/strip cam. Holley 850 4781-1 rebuilt. MT headers with 2-1/2 pipes stock distributor with lectric Ltd conversion Now the question is intake. I have an sp1 untouched or B4B with the divider cut down and a little plenum work , ports untouched I understand the sp is more of a top end intake and I’ve run one on a similarly prepped engine and it pulled well. Am I better off with b4b for street and occasional track use ? What say the experts ? Thx guys !!!
     
  2. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    What gears do you have? Will it have one of Jim's 9.5" converters? The crossover point is about 4500 RPM.
     
  3. steve murray

    steve murray Well-Known Member

    Oops knew I was forgetting something ! 373’s in a 12 bolt. Yes Jim’s 9.5 conv. 2800-3000 stall Larry
     
  4. Bens99gtp

    Bens99gtp Well-Known Member

    If u have the hoos clearance I'd run the sp1. With good gears I'd be willing to give up a little low bottom end.......the gears will help counter act that....t gain top end
     
  5. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    SP1. From the minute I tried this intake, I never looked back. Had it on my last motor with aluminum heads. Never noticed any loss in low end. There is supposed to be, but I never missed it. Not necessarily a bad thing for traction, especially on the street.
     
    Last edited: Aug 14, 2021
  6. steve murray

    steve murray Well-Known Member

    Awesome guys thx ! I was kinda hoping to hear that as that’s really what I wanted to run. I asked because I feel I have a really solid combo here and didn’t want to give up any on the intake ! I know b4b would work well, but really trying to max out this combination thx again
     
    Brett Slater likes this.
  7. Tom Haeffner

    Tom Haeffner Well-Known Member

    Keith Smith did this 20 years ago.Contact him and he will give you the details.I saw him do the test.It suprised us.
     
  8. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

  9. 87GN_70GS

    87GN_70GS Well-Known Member

    ranger and LARRY70GS like this.
  10. steve murray

    steve murray Well-Known Member

    Cool ! I’ll stay tuned … no pun intended
     
    87GN_70GS likes this.
  11. Buizila

    Buizila GO BROWNS !!!!!!

    I have an early Stg 2 B4B that I plan on running on my 464 build that I ran 10.40s with it in Buizila but was running a SPX and a Dominator. Be interesting to see the difference in performance
     
  12. rmstg2

    rmstg2 Gold Level Contributor

    I have ran both intakes, when I switched from the B4B to the SP-1 it knocked a solid 1 to 3 10ths off the ETs over several passes. If I remember the 60' times with the B4B were just a little better. On the street the B4B seems to have a better part throttle response.

    Bob H.
     
    ranger likes this.
  13. steve murray

    steve murray Well-Known Member

    Thx for the input bob , I appreciate it !
     
    rmstg2 likes this.

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