So I've been on the lookout for a good Dynaflow tranny ever since I saved the '63 Buick from the crusher in September. That car had been set up for Demolition Derby competition at the State fair, but the tranny crapped out at the last minute, and the guys (who worked at wrecking yards) were going to crush it. Anyway, this guy I know tells me he has a 401 with tranny that i can have if come over and pick it up. Says it came out of a 15,000 mile car that was wrecked 20 years ago. I ask why he's willing to give it to me then, and he answers that its now locked up cause it was stored outside and the cover somehow came off and exposed the carb to the elements. Anyway, I go get it yesterday and am feeling pretty good with it in the back of my pickup and I ask what year Buick the 401 came out of, and he tells me he thinks it was either 65 or 66! Man, I'm thinking then that this ain't a Dynaflow trans afterall! Were any of the 65 or 66 Nailheads 401's? How do I positively identify the tranny that's bolted up to this Nailhead?
If it's a '65 or '66 it's a TH400, or a '64 would have been a ST400....if so you got lucky. Ditch the Dynaslow. On identifying the trans, I think all Dynaflows have two cylindrical shaped castings pointing toward the bottom, near the front of the trans (on either side)....I'm sure someone has a better description.... Brian
65 could be either 401 or 425, 66 is 425 only. Both with TH400 trans. Dynaflow's have an aluminum bellhousing that bolts to the cast iron case. TH400 is all aluminum, 1 piece design.
Maybe a couple of pictures would help narrow down the identity of this nailhead stuff. From input received, it sounds like the tranny isn't the Dynaflow. But now I'm wondering if its the TH400 or the ST400. If it's the former, does that mean the engine is a 425 Nailhead VS a 401 Nailhead?
thats the switch pitch turbo 400 the best trans that G.M built in the 60's for my money! how about some nunbers off the block
That is not a dynaslow, that is the T-400. You can ID the engine by going here: http://www.buicks.net/shop/reference/engine_ident_63_75.html Look for the code on the front of the engine stamped at front lip of the valley cover. The T-400 is countless times better than the dynaslow, you should use that and you will be happy.
Yeah, I need to get the numbers off the block. Let's see.. I want to look for numbers at the very front and top, don't I, and not for numbers on the side of the block? I'll go take a look now.
Lucky sumbitch....some people look for years trying to find one of these! Tell you what, if you still want a Dynaflow, I've got 6 or 8 of them...swap you even! Brian
that's somewhat humorous.... I responded to an add in the paper on some Buick parts this ol chap was selling. (70's crap) and he said that he had some other parts in the barn that I could take if I wanted them. So I get into the barn an there is 2 sets of front drums off of a 65 rivi and a tranny, I asked him about these and we loaded em up in the back of the wagon......free with the purchase of a $50 set of chrome peices and a power steering pump for one of my other buicks. WOW..... that doesnt happen to often where they dont know what they have when it comes to buick drums n trannys...
[ QUOTE ] Yeah, I need to get the numbers off the block. Let's see.. I want to look for numbers at the very front and top, don't I, and not for numbers on the side of the block? I'll go take a look now. [/ QUOTE ] Yes. You want to look on the "lip" in front of the valley cover.
Well, using the Buick.net site referred to above by 38chevy454, I've been running the numbers off the block and heads... 'took me three trips from the warm house out into the cold before I finally figured out the engine displacement and year. The Buick web site has you looking for two alpha characters followed by numbers, such as AB123. Well on the front top of the block I found two number sequences. When viewed from the front of the block, there was an upside-down sequence reading "2J20712" and to the right of that was a right-side-up sequence reading "4J40 05839". That wasn't enough to decide the matter by using the Buick web site, so I went out again and found the head casting numbers: "11969914J". Well, that wasn't conclusive either, so I went out again and found a block casting number on the back of the block right above the tranny: "1349046" . So, I'm concluding that the block is a 401 afterall, and that makes me believe that the T400 tranny ought to bolt right onto the 401 engine that is currently in the rescued Demolition Derby Car shown here. I mean, the opening in the back of the 401 crankshaft ought to be correct as is, and no macining, adapters or anything else ought to be necessary. Is that the way you Nailhead guys see it? Hope that's the case. Then I will put it all together in either the '29 roadster or the '30 roadster pickup. Or maybe the 31 coupe IF the thing will fit. Some recent Web discussion about interference with the driver's side starter and the early Ford brake pedal/steering box has me wondering about that potential problem. Anybody dealt with that problem?
If you're using a 63 motor, it'll bolt up physically, but you'll run into issues with the flywheel. I don't think the TH400 torque converter bolts to the Dynaflow flywheel. Also, the Dynaflow cranks have a bigger pilot hole than TH400 cranks. You can grind or machine the TH400 flywheel to fit the dynaflow pilot no problem. After that alteration to the TH400 flywheel, it and everything else will bolt up fine.
[ QUOTE ] [/ QUOTE ] Fraz, I'm not sure that I am following you when you mention possibly grinding or machining the flywheel to fit the Dynaflow crank. Can you be more specific, PLEASE?
The pilot holes for the front of the torque converter on a dynaflow crankshaft are of larger diameter. The hole in the center of the dynaflow flywheel is therefore pretty big. When they switched over to the ST400's in 64, they re-did the pilot hole, making it a little smaller. The hole in the center is smaller. The ST400 flywheel center hole needs to be enlarged approx 1/8 inch in diameter for it to fit the dynaflow crankshaft. OR, you could see if the ST400's torque converter will bolt to the 63's flywheel. If so, you can forget everything I just said.
if you use the crank and flywheel out of the later buick nailhead and put it in the '63 it will bolt right up to the 400 tranny. with no problems. and you'll be in hog heaven...
It's not quite that simple...I have done the swap. The dynaflow doesn't have a flywheel, just a triangular shaped plate that bolts to the torque converter. The ring gear for the starter is on the converter. The 400 uses a conventional flywheel (flexplate). The flexplate will need to be machined to fit the larger snout on the dynaflow crank, and a bushing will have to be installed in the pilot hole, (the switch pitch 400 converter snout goes into the flywheel). Carmen Faso in New York has a bushing for this purpose...I used to have his info somewhere...so far I haven't been able to find it. The easiest way out is just use the later crank in the earlier engine...it is a direct swap. Here's a link on another board detailing the same swap. th400 swap info Brian
Found the info..... J&C's PARTS Carmen Faso 7127 Ward Road N. Tonawanda, NY 14120 (716) 693-4090 Brian
Kustum52, that sounds like the overall best solution, and the details to make it happen. When you're messing with things mechanical, the Devil really is in the details. Thanks a ton! Thanks to all the rest of you Nailhead guys too for your input.
Is it just me or do those stock Buick valve covers look like radiator top tanks? I've been seeing ads for modern tranny adapters for nailheads in mags lately.
They do look a little like radiator top tanks, now that you mention it. I pulled the transmission off the block tonight and put penetrating oil down the spark plug holes in the heads. Looks like I can't get the torque converter and flexplate off the back of the crank untill I'm able to turn the engine over, so I'm going to have to work at it. Found a tag on the side of the tranny that says "Super Turbine 400", and then has a General Motors serial number stamped in the tag. Although it's hard to see, the tag is about 4 or 5 inches back of where the trans fill tube enters the transmission body (behind where the grease is in the pic). That's there fist time I've noticed a serial number on a modern tranny. See them on my flathead trannys all the time.
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