401 vs 425

Discussion in ''Da Nailhead' started by KDML, Nov 7, 2009.

  1. mudchub1

    mudchub1 Well-Known Member

    Re: 401 vs 425 264

    what about 3 x 2.s on a 264,would the rochester 2gc be okay for it.where could i find the carbs,and what about the strombergs 94 97,thanks donny
     
  2. John Codman

    John Codman Platinum Level Contributor

    A single WCFB from a 322 works beautifully on a 264. The 264 will not need more then about 475CFM at 6,000 rpm. I love the 264. It breathes well with the same size valves as the 322 but much smaller displacement. It will pull to a significantly higher rpm then the 322, but does not have the bottom end torque of it's big brother. I used to quite regularly take down 324 inch Oldsmobiles, 292 Fords, and once a 347 Pontiac with my '55 264 with dual exhausts, a WCFB from a 322, and a Weber Aluminum flywheel. Other then that, the engine was stock.
     
  3. Airy Cat

    Airy Cat Airy Cat

    I run a Carter WCFB from a '55 Century on my '55 264 Special and it runs great.
    Getting back to the 401 vs. 425, it doesn't make much difference which one you run because of the crappy gasoline that's available... 92 octane.
    These engines were designed to run on 100+ octane.
     
  4. GS Jim

    GS Jim Platinum Level Contributor

    Doc, I have a '66 / 425 QJ intake. Will the same procedure be OK on a QJ manifold as well as a 401? I just need some advice here. Thank's.
    PONCH
     
  5. doc

    doc Well-Known Member

    Ponch,,,, I have never done a spread bore manifold,,,, but I was looking at one on ebay today and I did not see any reason that you could not do the mod.....I do know that some of the aftermarket manifolds for the BBB is open like that.... just be care full when you are doing the thing and make sure of every move before you do it..... have you run a stock qjet manifold before???? just trying to get a base line to gage the improvement by.... with those center pieces out of the way , that manifold should really be free breathing.... for sure the only restrictions would be the carb its self or the air cleaner... dont forget to open it up too......hope you get good results..... .2 or .3 is a bunch on the strip.....
     
  6. william.ali.kay

    william.ali.kay Needs more cowbell!

    Ponch, I too considered doing this to my spead bore intake. But after really looking at it, it seems the guys at Buick already tweeked the intake for ailheads in 66. Not to say you(we) couldnt improve on it, Im just the "If it aint broke,,," type of guy. Not to say I wouldnt ever do it.:Brow:

    The attatched picture says it better than I can with the 66 intake on the left. *borrowed the picture from another great site*

    If you do mod yours, please post pictures and results.
     

    Attached Files:

  7. funkyriv

    funkyriv Well-Known Member

  8. doc

    doc Well-Known Member

    that manifold that Funky posted will definitely flow some air.....:Brow: i dont know about cutting down the center divider though.... like one of the guys said before if it causes a problem you could fab a divider to plug the hole.....:laugh: :laugh:
     
  9. GS Jim

    GS Jim Platinum Level Contributor

    Well at least we know it can be done. I used a wooden spacer on my 350. It was a 4 holer. I just ran it through my planer to get the right size. The TV Kickdown was hitting the intake and wouldn't let it complete it's travel. It ended up around 5/8" thick. This was on a QJ on my 350 stock manifold when I did my engine swap. I had to keep an eye on the Air cleaner stud too. Didn't really need another hole in the hood. I also helped getting the secondary flaps out of the air flow too by bringing them up. Maybe I can give Denny Manner a shout, take him an intake and ask why it was left in there. He should be able to tell me. Let's keep in touch.
    PONCH
     
  10. wkillgs

    wkillgs Gold Level Contributor

  11. william.ali.kay

    william.ali.kay Needs more cowbell!

    That is some nice work there Walt.
    Do you recall about how many hours you have total in this?
     
  12. wkillgs

    wkillgs Gold Level Contributor

    Thanks William!
    I did it about 2 years ago....it took me a few hours to do it, and then a couple more hours until I was finally satisfied with it.
    Note there is a small connecting passage between the secondaries....that's factory. I did not open that up.
    I don't have before/after performance data since this was done on a fresh build. Someday, I'll swap this intake onto my blue car and see if it improves those 13.40's.:grin:
     
  13. 66larkgs

    66larkgs paul 66gs turbo nailhead

    hey walt do you think this would be a nice mod for the turbo 401? once i get all the bugs worked out of the car and painted this winter it to start to log in some data with upgrades and i have been looking into this mod. i have a bridgeport but i hate to to this to a hard to find q jet manifold if it is just for a few hp. i would rather port match.
    i would like to make a nice aluminum intake for the gs.use the elecco intake spaces as my base weld on four inch runners 1 7/8 or 2" round and make them oval and set it up like a smaller hogan manifold. maybe even two piece. set it up for my 4150 holley. being a turbo engine i dont think i would have a issue with atimization. Love to here your opinion and what you think. i know it would look cool.
    paul
    66larkgs
    turbo nailhead
     
  14. wkillgs

    wkillgs Gold Level Contributor

    Paul,
    I don't know if the modified intake would show as much improvement with a turbo.... you're already force-feeding the mixture, so you're less dependent on flow. If you want more flow, just crank up the boost!
    I'm thinking you may be better off using the Holley and possibly modifying the AFB intake, since there are lots of them out there.

    If you were to make a new intake, I wouldn't use the EELCO risers. The intake port is entering the head at an angle. Adding spacers would put another bend in the port....and that will make the flow worse. This is what the port would look like with spacers and stock intake:
    [​IMG]
     
  15. 66larkgs

    66larkgs paul 66gs turbo nailhead

    the only reason i would want to use them is to duplicate the flange. we could fly cut the risers @ an angle to help in that direct shot into the intake valve. i talked to a friend of mine who is amazing fabricator and i tossed it around with him and i think we are going to tak a shot at it. worst thing happens i put my stock intake back on... i have been reading up on runner design/port design, and material used and i am going to use a 6001 aluminum for the base and 3001 for the runners, they say it is easier to work with.:TU:

    Paul
    66larkgs
    turbo 401
     
  16. nailheadnut

    nailheadnut Riviera addict

    Perhaps there's a way to use a 364 intake on risers that have the "fly cut angle in them and attach it to your 401/425.. Then there wouldn't be the straight drop where the riser fits; to get the narrower intake to fit on the wider deck height, you'd have to create the riser with the angle built in. :Do No:
     
  17. 66larkgs

    66larkgs paul 66gs turbo nailhead

    why a 364 intake? i thought they dont make a aluminum intake for the 364?the reason i want to build my own aluminum intake is because of flow/weight/ and cosmetic. nothing wrong with building a sexy intake and have it funtional.... its like Going Fast With Class!!!!

    paul
    66larkgs
    turbo nailhead
     
  18. nekkidhillbilly

    nekkidhillbilly post whore

    id be interested in your intake if it has efi bungs
     
  19. nailheadnut

    nailheadnut Riviera addict

    Guess I didn't catch the part about you making your own intake. My suggestion would be for installing risers between the heads and an OE intake.

    Ed
     
  20. John Codman

    John Codman Platinum Level Contributor

    Before you take a grinder to a Q-jet manifold, be sure that this is what you want to do. The Q-jet manifolds are about the most rare stock big nailhead intake. The only year they were used was 1966. They do have some $$ value. I paid $40 for a good AFB manifold. I have seen Q-jet manifolds going in the $125 range. I wouldn't sell mine for that.
     

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