I have posted in the past but I'm looking for clarification on what exactly will need to be done to swap a '66 425 (getting ready to tear down/rebuild) into my 1957 Buick Special 3 speed manual Synchromesh. I'm under the impression that the manual trans is uncommon and I'd like to keep it. Before people jump on me the 364 is cracked behind the starter and the 425 was already pulled and I found it on Craigslist for cheap....so I figured, yeah, it's getting close to winter so lets do something dumb and go....
The 364 block is repairable by stitching. A 425 from Craigslist will be a crap-shoot as far as being rebuild-able goes. I would be VERY SURPRISED if it can be installed as is. The 6 bolt top cover trans. is pretty strong. JUST DON'T try shifting fast between 2nd. & 3rd. Tom T.
Thanks Tom, before I bought the 425 we pulled the heads, pan etc. mic'ed bores checked the bugger over and it seems good...it had good coolant, oil etc...hell, i'm not sure it wouldn't have run, minus rebuilding the quadrajet. I've read enough on this form to know your name, insights posted, parts developed and great work you've done, so should this be done? I really like the idea and I am committed to it but I need some expert guidance and source of parts to make aforementioned monster work.
Gooch, Too bad you didn't have an Endoscope, like a bore scope but used with a laptop, to put inside the cylinders with the plugs out. IF everything checked out OK then you could have done compression & leak down tests to determine the engines health BEFORE it was torn down. I guess now the next step is a refresh or a re-build. Do a search & you will find that these scopes are about $15.00. Something EVERYONE can afford for future use. Tom T.
Forgot, the flywheel will need to be balanced for the bigger engine as it's counter balance is for a 364 is approx. 3 1/2ozs. as opposed to a 401/425 which is approx. 4 1/2ozs.
If the 425 is similar to earlier Buicks, you will need an adapter pilot bearing for the stick shift. I don't think you will be able to reuse the one from the 364. Also (you probably already know this) The flywheel will bolt on in six different positions; five of them are wrong.
Great, thanks. I have the service manuals coming for the 425 so much may be clarified when I start reading. I was aware of the pilot bushing, but regarding the flywheel, how would one know which orientation is correct? Is this outlined in the service manuals? second to that; Referencing TelRiv above (post #6); changing from one weight (3 1/2 oz) to another is it just a matter of ordering the correct flywheel w/ 4 1/2 oz. weight? modification??
You "Should" be able to transfer over the pilot bearing/adapter, OR it may have to be turned down for installation in the 425 crank. Do you know the year of this 425?? JW '63-KW'64-LW'65-MW'66???What is the two letter code in front of the valley pan on the right side???? AND, ALSO the VIN number on the left side??? With these we can determine what year the engine is & what it came out of. The 364 flywheel will have to be balanced along with the rotating assembly when the engine is re-built. You will notice on the crank there is a hole/dowel pin type hole between the 6 bolts. Same on the flywheel. These holes need to line up to PROPERLY balance the rotating assembly. Tom T. .
Yes, the manual transmission in 1957 is an unusual, not rare option. Actual number produced seems to be unknown but 10% or less of total Special production. The ‘57 manual transmission available ONLY behind the 250 HP 364. It was not deemed strong enough to hold up behind the 300 HP versions of the 364 available in the Centuries, Supers and Roadmasters. With the work required as described above, in my opinion you will be very disappointed in performance and should probably immediately start collecting additioal 364 manual parts for spares and replacements. The best Buick manual transmission is a 6 bolt that was used in 54/56 Buick’s behind the 322 engine. They are available but pricy for a complete set up. They pop up occasionally on the BCA website. Just my 2 cents!
I don't know what the 6-bolt post means. I had a '56 with the big manual and it bolted on with four bolts. In '54 and '55 Buick used two different standard transmissions, the small one was attached to the 264; the big one to the 322. It was a very strong gearbox that was descended from the '37 LaSalle box. It is a box that must be shifted slowly; if you try to snap shift it, you better have a stock of transmission parts - you will need them.The bellhousings were different in '54 and '55 between the big and the small gearboxes. Either housing could be re-drilled to accept the opposite gearbox. Two of the holes (the top two as I recall) would line up for either box, you re-drill the bottom two.
In the post ( #2 ) above I said NO fast shifting between 2nd. & 3rd. What I meant to say was NO fast shifting between 1st. & 2nd. What happens is the internal linkage CAN'T operate fast enough & you end up in two gears at once. Even putting a pretty strong spring on the lever didn't help much. This in turn breaks the main-shaft. I know by experience MANY times. I installed a 59/401 from a '59 Electra in my '55 Special that was standard shift from the factory. I used ALL the used 425 parts from my Riv. during the rebuild including rings, bearings, cam, lifters, etc. In total I owned as MANY as 13 '55 Buick's at one time. It came with the 3.90 rear gears. As time went on it got the 2x4 complete set-up from a wrecked '65 Riv. GS. Then I made headers for it using headers for a '65 Skylark GS which I had to lengthen aprrox. 6 inches. It was pretty fast for the time. It would do from 60-100MPH in about 4 sec. in 3rd. gear. During that time it would break traction. Surprised MANY people, especially the Chevs. of the time. This type trans. is called a "Selector" type & is shared between Pontiac & Olds also. The Olds had a better synchro for 2nd. - 3rd. Tom T.
