1957 Nailhead and Dynaflow in a '56 Buick?

johnnyb56

Active Member
I've got a '56 Special sedan with the original 322/Dynaflow setup. The engine needs rebuilt and the trans. isn't that great either.

I recently met a guy at a show who had a '56 Special wagon. He said he'd sell me the engine & tranny (he's planning on installing a Corvette LS motor and drivetrain.) It's running what he claims is a '57 364. If I remember right, The '56 and '57 Nailheads have different bellhousing bolt patterns, so it's most likely a '57 or newer Dynaflow behind it. What I don't know is if he was running a torque-tube or a driveshaft- I would have looked under the car but it's been lowered. :confused: (Did Buick start using an open driveshaft in 1957, or was it '59?)

Unfortunately, the man didn't know much about Nailhead era Buicks and he just got the car, so he didn't know if the drivetrain had been modified for the swapped-in components or not. I DO NOT want to convert my entire rear end and suspension. If anyone has any info or ideas, I'd love to hear them.

Thanks,

John.

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:shield: 1956 Buick Special (Model 41)
1966 Chrysler New Yorker
1975 Chevrolet C-30 CC/DR
1976 Chevrolet K-10
1990 GMC S-15 Jimmy
 
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raycow

Active Member
1960 was the last year for the torque tube.

It's always kind of scary when you are trying to buy parts from someone who has no clue about what he is selling. The output shaft housing on a stock 57 transmission is longer than yours, so if your guy still has a torque tube the owner before him may have already swapped the output shaft and housing. If he has open drive, you already have the parts you need on your present transmission (assuming he has a Dynaflow). The only way to tell for sure is to crawl under and take a look.

Also, the block holes for the engine mounts are different between 56 and 57, so try to talk the guy into giving you all the parts between the block and the frame. He won't be needing them if he is going to install a Chevy engine. Lastly, just in case the guy is totally F'ed up and doesn't even have a 364, measure across the front intake manifold bolts on your engine and his. The 364 manifold is wider than the 322.

Good luck, and please let us know what you find out,

Ray
 

johnnyb56

Active Member
Also, the block holes for the engine mounts are different between 56 and 57, so try to talk the guy into giving you all the parts between the block and the frame.

Hi Ray,

Thanks for the information. I can't believe Buick didn't get a driveshaft upgrade until 1960- 5 years after Chevy...

I know for a fact the his wagon has a Dynaflow, but assuming the car still has a torque-tube, this swap doesn't sound too crazy...

I just had two questions-
- Will I have to modify and/or change out my engine cradle's mounts or anything like that?
- How difficult is it to change the output shaft and housing?

I'll call this guy when he gets back from vacation on Saturday, the 8th. Unfortunately, he lives 125 miles away, as I went to this show out of town, so we'll need to compare cars over the phone.

Thanks again Ray, have a good one!

- John


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:shield: 1956 Buick Special (Model 41)
1966 Chrysler New Yorker
1975 Chevrolet C-30 CC/DR
1976 Chevrolet K-10
1990 GMC S-15 Jimmy
 

raycow

Active Member
- Will I have to modify and/or change out my engine cradle's mounts or anything like that?

Yes, but if the guy really has a 57 engine in a 56 car, all the hard work has already been done for you. Just make sure to collect all the engine mounting parts off his car.

- How difficult is it to change the output shaft and housing?

As long as the car still has a torque tube, here again, all the hard work has already been done for you. I hadn't thought about this before, but it may be possible that the builder did the swap and left the 57 transmission intact. He could do this by swapping the 57 torque tube along with the transmission. The only real downside to doing it this way is that the torque ball could end up very close to the X-member, or possibly even inside it. The 57 torque tube is very easy to identify, as it looks "bent" about a foot ahead of the rear axle center section (there is a second U-joint inside the torque tube at that point). You will know as soon as you look at it.

If he did go with the complete 57 driveline, you will have to decide whether you want to take the rear axle apart and swap the torque tube, or to take the transmission apart and swap the output shaft and housing. My vote would be for the torque tube, but if you feel more comfortable working on the transmission, I won't try to talk you out of it.

Unfortunately, he lives 125 miles away, as I went to this show out of town, so we'll need to compare cars over the phone.

This is the only worrisome thing you have said so far. From your description, I honestly don't think the guy is knowledgeable enough to be able to accurately tell you what he has in his car. I am sorry to have to say this, but you should be prepared to take a drive to where the car is and look for yourself. If you like, I could PM my phone number to you so you could call me if you are having trouble identifying the parts or if you have any other questions.

Ray
 
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