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425 Nailhead or Flathead.

Discussion in 'The Hokey Ass Message Board' started by chopd54, Oct 27, 2011.

  1. mj40's
    Joined: Dec 11, 2008
    Posts: 3,302


    Nailhead porn! Put it in my 40 pickup.

    Last edited: Oct 27, 2011
  2. Joe Didio
    Joined: Oct 7, 2006
    Posts: 93

    Joe Didio

    Either engine will be cool in a Model A. For my 30 coupe I choose the Nailhead (57 364) followed by a T5 and a quick change. The car is going together for the final time and should be on the road soon.

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  3. Roothawg
    Joined: Mar 14, 2001
    Posts: 21,819


    I guess the era you are after would be your first decision.
  4. desotot
    Joined: Jan 29, 2008
    Posts: 1,845


  5. flatheadz-forever
    Joined: Jun 16, 2011
    Posts: 501

    from new jersey

  6. gearheadbill
    Joined: Oct 11, 2002
    Posts: 1,312


    just remember that with a flathead you "never spent so much to go so slow".

    I built a 32 3W with a built 425 Buick...tire-shredder x 10. Don't know about the earlier engines but most 401-425 installs into early Fords need a Gran Sport pan and oil pickup. They're kinda hard to come by; especially the oil pickup. Don't think they're reproduced. Used to be a guy in N.Y., if I remember right, Carmen Paseo (sp) who fixed me up with everything I needed. He's a wealth of info on nailheads.
  7. DualQuad55
    Joined: Mar 5, 2005
    Posts: 1,377

    from Epsom, NH

    My thoughts exactly. Depends on how else you are building the car. Figure out what era and style you are building, then the motor choice will become obvious.
    For all of you who have never driven a well built flatty in a light car, you might be surprised.
    Remember, 4 1/2" tread width can only put so much power to the ground...
    Both engines are about as nice looking as they come if dressed properly.
  8. nickk
    Joined: Feb 2, 2011
    Posts: 749


    id do the flathead
  9. teddyp
    Joined: May 28, 2006
    Posts: 3,197


    nailhead the best of both worlds
  10. 32coupedeville
    Joined: Dec 10, 2006
    Posts: 1,253

    from cincy

    nailhead. cost around the same to rebuild and you get way more power with the nailhead . oh and you get alot of torque to!
  11. Canuck
    Joined: Jan 4, 2002
    Posts: 1,082


    Red block Buick in a 30 coupe running original hood. Had to run headers and offset the engine 1/2" to clear steering using a Saginaw box and cross steer. Managed to squeeze in column shifting for a SP400. Space is kind of tight but it is all working out. Not as pretty as some shown but starting to clean it up.


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  12. Actually what rear end is a consideration but even a banjo will take a beating if it is the correct banjo. One of the fellas on here uses a banjo behind his built hemi the deal is that he uses a modified banjo out of a ton truck.

    Another thing to take into consideration is that a lot of old hot rods got updated when the valve in head V-8s started to become available. Looking through old albums from the 50s for instance you can find period perfect 30 or 40s built rods with hemis and what not in them. It was a common thing for a kid or even an adult rodder to capture someone elses old hot rod and throw a different drive train in it. Criuse it that way until there was cash for other more modern updates, sometimes the rest of the cash never happened.

    Basically this has happened in every era of rodding since the beginning. When a new trend happened the old rods were not just parked and left to rot they got updated.

    I have said this before and I will keep saying it until it sinks in if you want to know what was being done in hot rodding forget the magazine and look for old picture albums. The magazines are a good source of information I am not saying otherwise but they don't really show what was the norm they only show exceptional cars from whatever era.

    OK off my soap box for awhile.

    Instead of one engine or the other being the only true hot rod engine lets hear some pros and cons. What makes what the better choice.
  13. Pete1930
    Joined: May 5, 2006
    Posts: 321

    from Boston

    It comes down to what is most important for you. Both are great looking engines.

    For me --- my Dad had a flatty when he was younger, and it was the obvious choice for my Model A. It's what makes the car, for me.

    I just lost my Dad about 6 months ago, and we fired up the flatty together for the first time a few years back, and I got it on video.

    That engine will never leave my possession. :)

    Good luck,
  14. 31Apickup
    Joined: Nov 8, 2005
    Posts: 2,727


    It also depends upon how you are building your A, in most cases you'll need to modify the firewall with a Nailhead, but usually not for a flathead . I'm in the same boat for a A coupe build, my Dad has several flatheads he said I could use, or also a low mileage 1955 322 Nailhead. Haven't decided yet either.
  15. Dynaflash_8
    Joined: Sep 24, 2008
    Posts: 3,023

    from Auburn WA

    heres some inspiration for ya!

    <iframe width="560" height="315" src="" frameborder="0" allowfullscreen></iframe>
  16. My Riviera has the "little" 401 in stock form it makes 325 H.P. and 445 ft.-lbs. of torque. The car weighs 4,000 lbs and gets it pretty good for a big car. Figure 15 more H.P., 20 more ft.-lbs. of torque, and two tons less weight in a Model A, it'll be a screamer! Add headers, a cam, and improved induction, you'll eat most anything that pulls up to you.
  17. If it makes you feel any better about it I have an early '50s car that had been a blown gas coupe at one time. I am not a restorer per say so it doen't need to go back the way that it was prior to my owning it. We have set 3 different engines between the frame horns in an effort to try and decide which is best, finally ruled one out. So we are down to 2 candidates. Both with specific pros and cons.

    The other day I was talking to one of my buddies about it and he just smiled and said, "I know which one is going in there." I looked a little confused and said, "Which one?" he said, "The one that is closest to the cherry picker when the time comes."

    I am not a nail head guy or a flat head guy per say. Each one has its own virtues. Both can be as dependable as a hammer so rule that out as a con. Both are pretty heavy engines as well so rule that out also the nail head may weigh a bit more but not enough to make any real difference. Neither one revs well as they come out of the factory I think you could make the nail head rev better with a little less work then the flatty but still they both have that potential so rule that out. Niether one breaths real well the nail a little better than the flatty but again either could be reworked to breath better the flatty needs a lot of work to really breath but it can be done.

    Now getting down to brass tacs, if pure brute strength is what you are after the nailhead is going to be the outright winner, and dollar for dollar will remain the winner. Down side to that is that the nail head will also be a chassis twister in an A bone. So a frame boxing is a given with the nail head and no doubt a full boxing is your best bet. Also even though it can be done I wouldn't think that the Ford tranny would be your transmission of choice. It has been done a lot and to be period correct even for a '50s car the Ford tranny would be the tranny of choice. Not the best choice for the swap now but it would have been the tranny used more often than not in the '50s. Also to use the nail a rear end other than a banjo makes the most sense unless you are going to use the banjo that i mentioned earlier in the thread.

    The flatty is less powerful and to attain anything close to fifties or later performance it is going to be work. But that doesn't mean that it can't be mildly modified and cruised as is. It would be the easier of the two to swap in as it would take less modification to go in there. No need to box the frame, bolt on to a Ford tranny, later 30s banjo would suffice for a rear. Or you could throw enough at it to make it really fly, major port work, lighter pistons, more compression, stouter lower end if that is what you are after. They seem to be the engine of choice today for true retro rods.

    it is a hard decision, perhaps it will come down to the same choice as i make whichever one is closest to the cherry picker or maybe it will be a purley financial one or maybe it will just come down to which one is most ready to get on the road today.

    Either will suffice if they are the only options and both would be a good choice for the old A bone.
  18. mlagusis
    Joined: Oct 11, 2009
    Posts: 1,046


    Tommy Ivo had a Banjo behind a Nailhead in his T. I always thought he must have gone thru those rear ends pretty quick but back then they were a dime a dozen.

    If a guy runs bias ply tires the tires should break loose before anything in the rear will break any ways.

  19. The Raven broke his banjo with 7.50x16s behind a 305 that wouldn't pull an old sick woman off a bed pan. It just depends on which banjo you got like I said. Tommy may have been running the stouter 3/4-1ton rear, it isn't a new trick.
  20. ZZ-IRON
    Joined: Feb 28, 2007
    Posts: 1,964

    from Minnesota

  21. Xea
    Joined: May 6, 2007
    Posts: 59


  22. 35 Woodie
    Joined: Jan 20, 2006
    Posts: 194

    35 Woodie


    I love flatheads, have a 59A in my '35 woodie but I chose a 401 nailhead for my deuce hiboy now under construction. A '34 steering column cut at the firewall and two universal joints got by the starter with no problem. I indented the firewall to get the distributor in. Sanderson headers make the installation look good!

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  23. zman
    Joined: Apr 2, 2001
    Posts: 16,594

    from Garner, NC

    yep, before 53 and you'd go flathead, after for a few years and it, would be a toss up, by the mid to late 50's more likely to be a Nailhead...

    Lot's of Nailheads in A's the steering clearance is a non issue in an A
    About 100lbs. difference, I wouldn't worry about that... the power will more than make up for it.
    trans choice is super easy a SP/ST400 or a manual of your choice.:rolleyes:

    and slower... :D

    The pans are easy, you can use one from a 364. the pickup is being made, it's a non-issue. And it's Carmen Faso.
  24. Stevie Nash
    Joined: Oct 24, 2007
    Posts: 2,999

    Stevie Nash

    I just bought a 401 nailhead! I guess I opted for power and looks! Let's face it, a flatty couldn't get the Nash moving' like the nailhead will...
  25. teddyp
    Joined: May 28, 2006
    Posts: 3,197


    Nailhead too many slow flatheads out there that just look good once you go nailhead you never go back
  26. robber
    Joined: Nov 25, 2011
    Posts: 1,899

    from Colorado

    Congrats on the nailhead Stevie... they both have their place and following, but a nailhead is a great choice... just ask Tommy Ivo:D;)

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