OK I have cruised all the old post and discussed it with my buddies but still don't have a definitive answer! What are my options for a trans for my Nailhead I have two a 1957 364 and a 1965 401? I was originally thinking about updating to the 700R4 but the adapter kit prices are $$$. My buddies think the BOP trans should fit but everything I find here indicates otherwise. Then there is the Turbo 400 but what years and models fit what? I had finally decided to go with my first thoughts and use a rock crusher but the bell housing and clutch kits are again high $$$ and tough to find that will fit an overdrive tranny. Hey I am not trying to be cheap here but I do have a budget on this 32. What are the facts and some opinions please.
I heard that the 200r is a multipattern tranny.... not very strong though. I dont know if I would run either a 700 or 200 stock in my 65 wildcat, since it is HUGE and a torque monster... Maybe someone who knows something about transmissions could help us out.... That is definately not my specialty.
Nothing bolts up but a Nailhead pattern trannsmission. Look for a 64-66 full size Buick with a Nailhead and get the ST400 or SP400 out of it. They are TH400's with the proper bellhousing. 57-66 are the same bellhousing pattern, get the flexplate and converter with the transmission. No O/D transmission will bolt up without an adapter. Of course this has been gone over time and time again, there is plenty of information if you do a search. Nailhead transmission should find most of the threads. There is detailed info in the other threads as to the bushings, starters and such.
Unless you can find an original switch pitch ST 400, you'll need an adaptor to run a Turbo 400. http://www.transmissionadapters.com/Nailhead_install.htm They also make kits to adapt manual Chevy transmissions to nailheads. -Lee Atomic Radio www.atomicpinup.com
Yeah, what he said. Trannies with a B.O.P. pattern bell are NOT a match. AND...the pre-64 nailheads used dynaflows, so you can't just bolt up a 64-66 3 speed without some modification, so if you're on the cheap, better use the 65 401.
Find a 66 425, throw on a transdapt adapter # 0060 then drop a 700r4 behind that. I'm thinking about this for my Merc.
You listed a 4 chevy 4 spd (rock crusher) as another option. Changing a dynaflow over to a 4 spd is a lot more work than just getting a bell housing, flywheel and clutch parts. Ask me how I know...... I learned the hard way nailheads are externally balanced motors, so the only way to "do it right" is to take the motor apart and balance the rotating assembly. So...I'd stick with an adapter and run a 700R4 if I had to do it all over again.
I'm running a Super T-10 behind my 401. It is more work to mate-up, but I like gears. As you mentioned, external balancing is a must. -Lee Atomic Radio www.atomicpinup.com
You need a nailhead spacific bolt pattern tranny. Your choices are, Dynaflows, nailhead T-400's [with and without SP], and manual tranny bellhousings. Anything else will require an adaptor. The nailhead was offered up to the '67 model year, and it was used in musclecars [GS] and I'v heard of it being found in a few factory pick-up trucks. Unfortunately, there are a couple differences within the nailhead lineup. Some of the flexplates/flywheels wont interchange between early and late motors, so a little homework will be required before you lay down your $$$$
Right! 64-66 ST400 transmission flexplates will bolt to 64-66 Nailheads, but (I believe) the flexplate crankshaft hole needs to be opened up for 57-63 Nailheads. Don't even bother with 53-56 Nailheads as they have a larger bellhousing with different bolt holes. And with the nailheads being externally balanced it would be wise to tear down the 364's and get the crank/flexplate machined and balanced, if you choose to use the earlier nailheads. Your easiest bang for the $ is a 65-66 ST400 bolted to your 65 401 nailhead. No mods needed. In any event DON'T GO WITH THE "FLOW"!
The only Nailhead that made it into the truck lines were 322's and that was late 50's. And just to clear up any confusion your up to '67 comment may cause, '66 was the last year of the Nailhead.
What is included in the transdapt adaptor? The 401 I have is the same as a 425 block. What kind of $$
Those adpaters are $675 To much in my book, the Nailhead has more than enough torque to pull a nice tall gear and still have excellent acceleration....
The website says $149.15. I'm waiting on partslinger on here to install one behind his 401 and see what it takes.
zman pretty much has it covered..................I have just started making templates to make my own adapter for a Chevy bellhousing to a 401. I have a ST400 on it now but I gotta have a stick! I'll post pictures as soon as I start, but this may be a week or two.
GM made the Nailhead case as a universal trans sold to other motor companies for about 3 years after the last Nailhead was made. Supposedly bought by Rolls and Jaguar among others - can be found in some Jeep Wagoneers, oddly enough adapted to a BOP pattern Buick 350 which they also used for a few years. The trans has to be converted from 4 wheel drive to 2 wheel drive, but I believe this can be done with just a tail housing change. This information, in more detail, can be found elsewhere here on the board with a little searching.
Bendtsens makes a bellhousing to run a T5 also. hot rod pro on here just got me one for my 401 I am going to run in my 27 coupe. the bellhousing, throwout bearing and fork was $500 and some change. definetly worth it to run a stick. S.
The problem there is depth problems. The Nailhead has about 3" of bell cast into the block. So the Chevy bell and the adapter requires the use of a big spacer. The bellhousings are about $350, well worth it if you ask me. Here ya go, I end up posting this about every 6 months or so... A source for TH400 trannys: wanted to give everyone a heads up on a good place to look for TH400 transmissions. keep an eye out for jeep pick-ups and wagoneers 1965 to 1972. they have the same bell housing as a 401 nailhead and are th400's. you can unbolt the transfer case adapter and bolt on a 4" tailhousing and your ready to go! the holander number is # 1331, so start looking. i had never seen one till today and stumbled across one. Also Rolls and Bentley you are correct about this trans bolting up to a nailhead, but the output shaft should be a course spline on the jeep & about 3.75" longer than a 2x2. Dave the one i found was out of a 1970 jeep p/u but the output shaft is the same length and spline as my 65 buick trans st400 i have! what do you think the deal is with that! maybe it was changed or something. Yea, sounds like someone changed the shaft to be able to use a later GM transfer case. Good deal for you tho. Just checked on the jeep cores I have & they both have the long course spline output shafts. But you will want to overhaul it anyway, so thats the time to switch shafts.I got tons of the 2x2 shafts if you need some. Dave Most of the nailhead cases in Jeeps have the fine spline short shaft used with the 4" extension housing for Buicks. the exception being the Quadratrac transfer cases. You can also find them in CJ7's until 1980. Even stranger, the Jeeps with a 350 Buick in them used the Nailhead case, with an adapter to bolt to the 350. this is the adapter that might be reversed and used to fit a BOP stick housing to a nailhead. Don't know that it would work, never tried it, May be impossible, I really don't know. The guts will interchange from any T400 to any other T400 case. there are differences. The Buick valve body will hold the trans in the gear selected, and not "blow" shift like a chevy T400.The ST400 parts will fit too, with qualifications. you have to use the ST pump with the ST convertor, and the is an orfice plug that has to go in an oil passage behind the pump at the top of the case. Also, you can use a ST 300 convertor in a ST 400 to get more stall out of the trans. The ST 400 convertor is 13", the ST 300 convertor is 11"
Do you know which clutch disk, pressure plate and fly wheel you are using? also the bell housing model and did the throw out bearing and fork come with the bell housing? I am seriously thinking of going this direction but others in post doubt the T5 will hold up to the nailhead torq?
The T5 will hold up well until the first time you dump the clutch. Then you will need a shovel and some speedy dry. The 364 can be used with the 64-66 Buick trans like Zman says, you will need a crank hub adapter, flywheel, and modify the starter or space the starter forward about 1/2-5/8". Then you would need to have the flexplate balanced to match the 364 motor. I think it is just about a half ounce lighter on the balance weight already present on the factory flexplate. I could double check if you go this route and need the info. No need for overdrive, just some low 3.00-3.42 gearing and you will be fine with the light car. If you end up with the switch pitch trans, this will be more than enough to reduce the tread life of the rear tires in a hurry.
Bendtsen's site lists all the info... This bell housing will allow you to bolt a Muncie 4speed/Borg-Warner T10/Saginaw3 and 4 speed or any other manual transmission that uses the common GM bolt pattern to your Buick nailhead engine. It will work with either type of stock flywheel. Flat or recessed. Both of these are difficult to find. We also sell a replacement flywheel , clutch kit, pilot bearing adapter, and clutch fork. The flywheels are brand new, balanced units. They take a common Chev 11 inch clutch assembly. The following LUK clutch kits work with this flywheel: If you are using a S10 5 speed with a 14 spline input, use LUK #04-086. If you are using the common 10 spline Muncie/Borg-Warner/Saginaw input, use LUK #04-049. If you are using a transmission that has the 26 spline input, use LUK #04-020. These clutch kits come with a short throw out bearing. You MUST use a long throw out bearing. Some common industry numbers for this bearing are FM 614037 and CR N1086-A. The clutch fork # from GM is 3765372 or 15687296. The pilot bushing or bearing is the same as used in most 55 and up Chev V8/V6/L6 engines. When using our flywheel, you must use a 1964 to 1966 stock Buick nailhead starter. Many starter catalogs incorrectly show that the starters are the same from 61 to 66. Many rebuilders also put either starter in the same box. You must use the correct starter. Ive enclosed a picture of both starters so you can ID the right one. The older starters can be used if you install the correct starter drive from the later starters. http://www.transmissionadapters.com/
I didn't read through every post but have gone through this already. Us ethe 65 401 and the 64/66 s/p tranny,sarter,flexplate,torque converter. If you go with one of the other nailheads it can still be donejust more problems. starter mates up differant on the 364 and you have to adapt the later starter for a s/p 400 to it. I have gone at it several differant ways over the years. Pm me and I'll go into detail for each one.
WOW guys! Thanks for all the feed back it was nice to get all positive ideas! Still a lot to digest and it dosen't look like there is an easy or cheap way other than the SP400 on my 65 401. I am still looking at getting what I need for a standard trans or a kit to install the 700R4 plus keeping my eyes open for a rebuildable SP400. Thanks
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