I've got these parts that I collected many years ago and now am ready to begin putting them together. The 425 nailhead came out of a '64 big convertible, along with the T-400. The engine/trans are still together and I'm guessing that they have never been apart since they left the factory. I pulled them from the car about 20 years ago. Note that the engine is stored waaaay back behind much "stuff" and I'll have to spend several hours getting it out when the time comes. Therefore no pix to post here. The ST-10 is the one I've posted about in another thread. I bought it as in those pix; also probably 20 - 25 years ago. I have a bellhousing, flywheel, pressure plate, clutch disk, and throw-out bearing that I snagged off of that auction site; also probably 20 years ago. These parts were purported to be from the same car and I have no reason to doubt that (who could/would have collected all these parts piece by piece?). Having the clutch disk and throw-out bearing will be good when I go to the parts house to ensure I get identical parts. See storage note above regarding the engine. No pix here either. Here are my concerns (and I don't think pix are required to answer these): 1. Bolting flywheel to crankshaft. Does anyone know if bolt patterns match? Yes; I'll know when I dig all this stuff out, but any gurus out there that know? 2. Pilot hole. I'm guessing that the crankshaft has no pilot hole. Won't any good machine shop be able to put that hole there? Will the crank have to be out of the engine to do this? 3. Balancing: internal? external? Anyone know what problems I'll have with balancing? 4. The 425 has the original 4 bbl carb/intake. I have an original Buick cast iron dual quad intake I plan to use. I'll buy a couple of new Edlebrock carbs (the smallest they sell) for it. Anything I need to know regarding carbs? 5. Any problems going from automatic to manual transmissions? I'm supposing that I'll not be able to know if input shaft length & pilot bushing size are compatible until I try to bolt it all together. I'll have to cross that bridge at that time. I'm trying to solve as many problems in my head before I start screwing parts together only to find out I should have made better preparations. b-t-w; this is all going into a full fendered '31 2-dr sedan. I collected these parts to go into a '26 T modified I was planning. When my best friend died and left me the Model A I sold the T tub to another hamber and switched plans to the '31.
you probably need to get the parts out and take the trans off, and look at everything...you know how we are here, about pictures
I don't know about a Buick, but a little over 50 years ago, my folks had an Olds manual transmission car with a bad 330. The boneyard replacement wasn't drilled for a pilot bushing. At that time, he was able to find a shop that was able to drill the crank without tearing the engine apart. Whether you could find a shop to do that these days.....I don't know. Gary
Watching intently. I may be doing the same thing if the turbo hydro behind the 425 Nailhead in my '33 pu doesn't work. I've already installed a clutch pedal, you know, just in case.
Atch, As far as I know, the crankshaft bolt pattern is the same for the 364/401/425 from 1958 up. The pilot hole and the flexplate flange on the crank changed in 1964 when the Dynaflow went away and the ST400 started. I would start by measuring the flange OD and the flywheel ID to make sure they match. The 64 ST400 had a one year only valve body, and the switch pitch in 65 and 66. I think there was also a block change for starter mounting in 1959. Russ Martin can help there. I believe the standard/automatic crank is the same, so a standard pilot bushing should work. The nailhead is externally balanced, so the flywheel must be off of a 401/425. I am not sure Buick had any standard shift shift cars past 63 (other than the GS), so I would make sure the flywheel is not from a 364 engine. The flywheel will bolt on in any orientation, but should have an index hole that lines up on the crank. I pondered the same idea of going manual on my 401/ST400 combo, but decided to keep the auto, even though it is a 64 model. The 401 is still in the floor, and I have a 61 364 apart, so I can measure the crank flanges if you want. Most of the gurus claim that the carbs, even though dual, need to stay at least 650 CFM. I think Jon (carb king) can steer you in a direction of linkage.
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