Nailhead ID

Discussion in ''Da Nailhead' started by Spicolli00, Jan 7, 2010.

  1. Spicolli00

    Spicolli00 Member

    I found a Nailhead with the block casting number of 1364705.
    Its listed as 401/425. Head casting number is 1374603 also 401/425.
    The trans is auto unknown as of yet! I havent see the combo (its still in the car) owner gave me the info via e-mail.
    The car is a 1965 Wildcat 4 door. The owner is going to check the block code in the morning.

    My question is are there a few blocks that are share the 401/425 casting and can the 401 blocks be bored to the 425 since it is the same block cast?

    I have been told that a 401 cant be made into a 425 without pos. heat issues and thin walls. BUT. if this is the same block cast wont it be same block just diff. bore? Same wall thickness

    I'm a nub. in the nailhead information aspect. can you help educate me? :)
     
  2. its a 66 motor
    heads are 603's
    tranny would be a sp400 trans
    as far as making the 401 into a 425
    i wouldn't for what you have mentioned already
    Greg
     
  3. 1967GS340

    1967GS340 Well-Known Member

    I think the way it goes is that the early 401 / 425 castings were different internally for cooling. Later ones were all with the same casting.
    I could be way off base since that is something that I was told and not something that I researched.

    I think that you want to look on the front top of the block on the passenger side for a alpha character code. You can tell what the motor is from that.
    You may want to send Doc a message. He's been a world of help to me in learning about the nailhead.

    Either way, it's going to be a cool engine.
     
  4. nailheadnut

    nailheadnut Riviera addict

    To get 425 cubic inches from 401, you'd have to bore it 0.125". Boring a 401 0.060" is pushing it.

    Here's a link from the Team Buick site that will help you ID your engine. Casting numbers really mean very little when ID'ing an engine. The stamped numbers are what you need.

    http://www.teambuick.com/forums/view.php?pg=indent_engine_where

    Transmissions have a tag on them that should have the year stamped on it. Easy to ID them.

    Ed
     
  5. Spicolli00

    Spicolli00 Member

    Thanks

    Greg, David and Ed

    I would really like a 425! But, If i could build a 401 with just as much power i might consider it.

    I should find out more tomarrow. The owner is getting me the code and looking at the trans.

    I plan on installing a 401/425 nailhead, 354/392 Hemi, stroked 360 or SBC stroker 383 in a 1933 5 window Plymouth.

    I just cant make up my mind right now! I have some time to plan so i'm in no hurry! I just really like the look of the nailhead and the Hemi the best.
    Looking for the right deal. SBC is the cheapest but every one does that! :)

    I think i can get the 1965 Wildcat for low cash then sell the rest of the car for a parts car?

    I might have a line on a 1966 Riv. GS but, they want $2000.00 for it and all i want is the 425 and trans out of it! i dont tink i can resale the rest to make up the diff. in cost for it!

    I was just thinking if a block is the same casting. It would be all same block But the bore!

    I will post more when i find out more info!
     
  6. 1967GS340

    1967GS340 Well-Known Member

    If the 425 is a good one, $2000 while not cheap isn't way out of line either. Shop around and you can find one for $1000 to $1500. 63 and older will be dynaflow transmission cranks and you will need a bushing to run a newer transmission.
    Of the engines that you are looking at, the Nailhead and the Hemi have the hot rod look that you want. The Hemi being the more common at car shows and probably the more expensive engine to work on, although there are probably a lot more parts for it.
    The 401 or even the 322 should make lots of power for as light of a car as you are planning on putting it in and you will have a fairly unique car with a true vintage hot rod looking engine.
    Think dual quad's!
     
  7. doc

    doc Well-Known Member

    Think on this,,, a .040 over 401 works out to 410 cubes.... not that much difference,,,, I really like those little coupes,,, there was one in our family for a long time.... bone stock,,,, really babied,,, dont know what happened to it....
     
  8. Spicolli00

    Spicolli00 Member

    With the restrictive head on the nailhead would it be better to build a 401 instead of 425 as it will get more free flow exhaust. OR can a 425 heads be worked to flow free to over come the restrictions?

    Also, What would a good buick riv. GS go for without its nailhead and trans?
     
  9. nailheadnut

    nailheadnut Riviera addict

    In 1966, the GS package on a Riviera was mostly a dress-up option. The two 4 bbl engine was only offered as a factory unit after March of '66. That engine code will be MZ. The intake and numbers matching carbs are probably worth a grand by themselves (if they're still there.) As far as getting your money back, these are the things you want to look for on the GS: The large chrome pancake air cleaner, the finned aluminum rocker covers, the BS coded transmission, and the 3.42 Posi rear end. (GS badges are being reproduced.) The GS had a sport suspension, but after this many years, the springs have probably sagged and the shocks have been replaced. One thing was unique to ALL '66 Rivieras - the Quadrajet carburetor and intake manifold. The manifold is probably worth $125-175; the carb is only good for someone wanting a numbers correct Q-jet. Later Q-jets were much imporved and had larger CFM's. In '66 the body/chassis was new therefore the posi rear end fits 66-up models (14 bolt, 9 3/8" pinion,) it won't bolt in anything earlier. The posi unit itself my be worth $300-400, but you'd have to remove it from the carrier. If someone were wanting to build a GS clone, you could get some of your money back, but there's probably a lot of the stuff you'd want to keep for your own hot rod.:confused:

    Given a choice for a Plymouth hot rod, I'd go for the Hemi- Mopar powered by Mopar. Even though this is a Buick forum, brand loyalty is one of my vices. Ford powered by Ford, Buick powered by Buick, etc.., etc.

    Ed
     
  10. Spicolli00

    Spicolli00 Member

    The data code for the wildcat is (LT). So from what i understand it is a 401! I also has the 3 speed auto!
     
  11. RipRohring

    RipRohring 53 SUPER V8 12 Volt

    Hi All: Regarding a 401 to 425 Cu In growth - can that also be attained by increasing STROKE ? Rather than all by boring and oversized pistons ? Just aa question to facilitate the discussion, which I read with interest.
    Of course, I have a 322 C.I. :3gears: Nailhead - and I listen a lot - trying to pursue a mild noise level increase, and a slight power increase (real or faked ?). . .

    Like I said, in an earlier post, I'm not looking to run over a kindergarten class out for a walk close to the road on the sidewalk.

    That sort of infers that I'm looking for a disc brake upgrade for the front wheels at least ? :kodak:

    Rip Rohring :Comp:
     
  12. wkillgs

    wkillgs Gold Level Contributor

    LT is a 1965 401.
    Good engine, used in several application. They were all 325 hp, same as the GS LR code. All have the same components.
    You do have the most desirable 65-66 ST400 trans with the 'switch-pitch converter!
    Rip...Stroking a Nail is possible, but the heads still limit the RPM potential. Even more so as you add cubic inches.
     
  13. Spicolli00

    Spicolli00 Member

    I found a 1964 non-running ("but was running a year ago") 425 with the ID code KW. I has a after market 2x4 on it (looks aluminum)! It has an auto trans.

    My question is what transmission would be stock on it (2 speed OR 3 speed 400 with VP)? The price is a little high for me.

    So what would it be worth?

    Thanks
     
  14. wkillgs

    wkillgs Gold Level Contributor

    1964 was the first year for the ST400, but it was different than the 65-66.
    64 did not have the switch pitch converter. Also the valve body and even the case is different.... it's a 3 speed but the shifter only had 2 foreward positions: Drive and Low. Kind of an oddball.
     
  15. Mr62Buick

    Mr62Buick Guest

    To me, boring a 401 to a 425 is really not very much 4 3/16" bore to 4 5/16" bore. That's 1/16" all the way around the piston. If it was me, I would bore it to a 425. BTW In 1989, I bored my 401 +.040 and it was a 409 cubed motor.


    Here is my quick mathematical formula I created in college.

    bore x bore x stroke x pi x 2= CID of v8

    It was WAAYYY more accurate than the formula they gave me in the book.
     
  16. lapham3@aol.com

    lapham3@aol.com Well-Known Member

    I guess the reason for so many wanting the 425 is 'bigger' is better. I have some 401-425 and a couple 407 in big Buicks. The cam/tuning/exhaust and carb choice can easily mask the diff in cubes. Nobody can readily guess which engine is in the car's after a drive-
     
  17. doc

    doc Well-Known Member

    Dan is right on... the biggest difference is with bone stock engines....
     
  18. wkillgs

    wkillgs Gold Level Contributor

    To be sure, the cylinder thickness must be measured with a sonic tester.
    IIRC, wall thickness is generally about 0.200". A 1/16" over bore will remove a THIRD of the cylinder wall and could be disastrous!
    Word on the net is that even a 0.030" overbore may be the max on many blocks.
     
  19. nailheadnut

    nailheadnut Riviera addict

    Mr62...

    As everyone has said, you can't bore a 401 out an 1/8". If you did, you'd have no cylinder walls left. The only thing you could do would be set the block out, let it fill with dirt and water and grow flowers in it.
     
  20. ahhh65riv

    ahhh65riv Well-Known Member

    The only safe way to bore a 401 to 425 is to sleeve it! Furthermore, if you plan on doing anything more than honing on a rebuild job a test of the wall thicknesses should be a high priority. There were a lot of "core shift" issues besides just thin wall castings.
     

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