Recently located a 1964 389ci with an automatic trany..., is this trany the same as a "Switch Pitch" (desireable type) ? I found a stick set-up for the 64' Poncho engine and I'd like to run that 4 speed and a friend would like my auto trans for his 1959 401 Buick. Would the 1964 Poncho automatic trany bolt up behind a 1959 401ci Buick...? And would it be a good automatic to have behind a 401 Buick motor...? Mark
Will not bolt up. Bolt patterns are different. Nailheads have a bellhousing extension cast into the block, Pontiac won't have it. Nailheads kick ***, but the stock transmissions for them are **** till 65-66. It's getting better now that there are a couple people making adapters. www.transmissionadapters.com www.phoenixtrans.com The reason that GM created the TH400-series trans was to handle the torque of Nailheads. So yeah, nailheads run fine with autos.
In 64 the Poncho was available with Powerglide, a Dual Coupling Hydramatic as well as a one year wonder called the Roto Hydramatic 375. I have no idea how the last 2 relate to the rest of the Hydramatic family. You can get a code off the tag or name plate to ID. Pontiac got the TH400 in 65. The reason that GM created the TH400-series trans was to handle the torque of Nailheads. So yeah, nailheads run fine with autos I sort of doubt that statement. GM would have followed the money and it wasnt just in Buicks; besides the nailhead was already on its last legs. Chevy needed an auto that would handle the 409 as well as the new in 65 396 as well as the soon to appear 427. Going to one ****** across all makes made more sense.
if your buddy wants to hook up a turbo behind his buick instead of wasting an insane amount of money on those adapters just find a th400 with the round buick bolt pattern out of any 64-66 buicks with 401 or 425s when you get that ****** take the starter and flywheel also. all you need to do is cut the id of the flywheel so it fits over the flange of the earlier crank. bolt on the starter and make a bushing that goes inside the snub of the crank and outside the snub of the torque converter make it the correct thicknes and bolt on the trans. i can get the dimesions of it. it works good there are three of them that run around st paul.
I recently sold my 1964 grand prix (I miss you baby) and it had the roto-hydramatic (also known as a slim-jim) and this was the most common automatic in the Pontiac line-up that year. It is considered a piece of **** by many (mine was a champ though) and finding someone who works on them is harder that finding the parts. Wagons, police, taxi, and other heavy duty applications got the super-hydramatic, which is a much better ****** but harder to come by. Either way, if you have a 4 speed then I say pitch that slush box, then go forth and kick some ***! My box-stock 389 had awesome torque... can't imagine how much quicker she would have been with 4 speed and maybe some tri-power lovin'!!
Actually Fraz's statement is true. A Buick engineer designed the 400 and was used in 64. And it was later used by all of GM. And yes the dual coupling hydro was junk. Its also very expensive to rebuild nowdays
A Buick engineer designed the 400 and was used in 64 You got a reference to support that? Not wanting to start a pissin contest either, just for my own file of trivia. The way I read is that it was a joint effort a**** several divisions and it wound up on Buick AND some Caddys in 64 as those brands were often the proving grounds for new ideas.
The 1st year of the Buick st400 automatic was actually 64, but unlike the 65 & 66 st400's, the 64 was not a "switch pitch" version. It should also be noted that although the bolt pattern is the same, pre-64 nailheads (because they used dynaflow trannies) require a pilot bushing / flywheel modification in order to use an st400.
Not ment to be a ******* contest. I read an artical on it, which I tried to find last night but still havent. Of course we can verify that it was first in a 64 buick or should we say the initial design was.
All ******s are buildable, but most people chose not to build them because they are unreliable and cost an arm and a leg to rebuild (Dual coupling that is).
OK..., the trany number is P64 12431B, is this trany buildable? Thats the Roto Rooter 375, originally installed behind a 64 389 with 2bbl. Buildable as lawn art maybe. Of course we can verify that it was first in a 64 buick or should we say the initial design was. Even tho the evidence shows it was also in the 64 Cad 60 & 63 series as well as convertibles? The only difference was the name they used. I'll grant you that it was probably first tested in a Buick back in 62 or 63 or however long the design phase took but for 64 models the suits took over. 64 was apparently a do or die testing time for various out to the public production GM ****** designs as the HP/torque race was on a roll and Caddy had the most torque with the 429.
I have a 64 Grand Prix with a Hydromatic trany. After 53 years the front seal was leaking but it shifted just fine. I pulled the trans to have the seal replaced and then I thought, while I had it out I should check into having it rebuilt. I bought a total rebuild kit with all new plates and the internal filter for just under $400. My mechanic neighbor charged me $200 to rebuild it and that included dipping it to clean it. I tipped him $100. Nice to have good neighbors that also restore cars.
The Roto hydro was used in all the short wheelbase Pontiacs (Catalina, Ventura, 2+2, Grand Prix) from 1961 to 1964. The Starchief and Bonneville (long wheebase) got the dual coupling (super hydro) in those years. Had nothing to due with police, taxi,etc. Contrary to what a lot of people think, the dual coupling was way better than the Roto!
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