1955 nailhead compatibility

Hi group, I have been out of touch for a while, but I am back in the loop. I am going to look at a nailhead and transmission soon out of a 1955 buick. I need to use it as a temporary set up in my 63 rivi untill the original 425 gets rebuilt correctly. I need to know of the differences between those years so I can drop it in easily. Thx Vito

 

55 engine and trans will not bolt up .
55 trans used a torque tube drive shaft, that is a
close unit.
The bolt pattern for the trans on a 55 is different, so you
would not be able to used the later trans.
Best bet is a 64 to 66 engine, 59 to 63 will
work, but they use a dynaflow trans.
Bill

 

I'd look for a 61-63 Dynaflow as a torque tube was used with Dynaflows through 60. Any 57-63 Nailhead would have the correct size bell housing and crank flange for the non-torque tube Dynaflow. 53-56 Nailheads have a larger bolt pattern that fits a larger bell housing on the earlier Dynaflow transmissions and 64-66 Nailheads have a different crank flange and ring gear arrangement for the ST400 trans (ring gear on flexplate instead of on converter). Clear as mud right?

Cheryl

 

Cheryl is correct. I'll make it simple - it won't work. But save it, a decent '55 Dynaflow that works well will have a worthwhile resale value.

 

What John says will go for the engine, too

 

thx for the input guys, well i guess i'm still in search for a running nailhead and trani 63 to 66. if anyone has an arizona connection, thx in advance. vito

 

Re: 1955 nailhead compatibility UPDATE HELP

Hi group, well i had to make a move on the 55 nailhead. I could not pass it up, it ended up being a rebuilt perfect running engine and trans for $500. With that $ spent i have to go against the advice given and ask for direction. I will consult a local guy for help but his buick knowledge is just... Ok. Please give me a few challenges i will come up with in dropping this engine and trani in the 63 rivi. The only thing i will not do is alter any components under the hood of the rivi, anything else i cant imagine being a show stopper unless i hear something different from u guys. Remember this is a temporary engine for hopefully only a year till the 425 is rebuilt. Thx vito

 

You will need to use the current Dynaflow transmission in your Riv with the bell housing and converter from the 55 Buick Dynaflow transmission. Or, find a 61-63 Buick Dynaflow and do the same with the 55 Dynaflow and converter while your 63 Dynaflow is being rebuilt.

Cheryl

 

Hi Cheryl. The trani behind the 425 is not a dynaflow. Pretty sure it's a th 400. We just tore the engine down today, an excellent candidate for a rebuild when the money is there . So i guess what your saying is if I find a 61 thru 63 dynaflow I will avoid driveshaft and trans mounting challenges? Thx vito

 

63 Riv came with a dynaflow. Does you engine have the ring gear for the starter on the flex plate or was it on the converter?

 

Hi cheryl, the ring gear is on the flywheel.

 

Well, then it has a later ST 400 flex plate converted to fit the original engine and replacement ST400 trans or the entire engine and trans have been replaced with a later 425 and ST400. What is the two letter code on the right side of the front valley pan rail of the engine and the two letter code on the tag on the left side of the transmission?

 

7k1001111 top of block 1364704 at distributor . Need to get to the trani. Thx Vito

 

Wasn't the st400 offered the later part of 63?

 

No

 

7k1001111 is the serial number of the car original to the engine. 7 is Riv, K is 1964, 1 is Flint Mi assembly plant and the rest is the series number in the line. There should be a code on the passenger side of that rail as well. kT for big car 64 401, KW for big car 64 425 single 4 bbl and KX for big car 64 425 2x4.

The Trans code will be BN or BQ if it is from the same donor 64 Riv depending on if it was a single 4 bbl or 2x4. The year should be on it as well.

HTH - Cheryl

 

hi cheryl, first i want to thank you for working with me on this. it is a KW block , the 7k... matches the vin on the title, and the trani plate is BL the yr 64 the other identification is 408 and 7901 on that plate. the date of first registration is 12/63 which may explain some things. if i knew how to post pics i would send them. im still looking for more feedback on the 55 engine and trani i purchased and i'm assuming if there is no feedback i should not even think of trying to drop it in the 63 riv and may have to sell it. any thoughts? thx vito

 

Vito, it seems you have a 64 Riv. The model year starts production late in the year before the the beginning of the year. Yours is an early 64 that may have been built in 63, but the vin# is for a 64. Your trim tag would tell us what month and week the car was built. I see the BL listed as 64 425 column shift ST 400, but stranger things have happened. A build sheet or protect-O-plate would tell that tale.

Now that we know you have a ST400 driveline, you would need parts from a Dynaflow driveline to make your 55 work. That would include a 61-63 Dynaflow (needed to sit in place of your open drive 55 dynaflow and requires a swap of the trans bell and converter to fit your 55 engine), 63 Riv trans crossmember, mount and linkage (different then the ST 400 stuff) and the 63 Riv driveshaft (different length and yoke then the 64 Riv driveshaft). Some mount fabrication might also be needed use the different crossmember on the X-frame. So you would basically need to adapt a 63 Riv to your 64 Riv, but with a smaller much less powerful engine. Also I am not sure the exhaust headers would clear the Riv frame and they are not the same as the 57+ manifolds (different exhaust port shapes). So, as you can see, this is a real project in the works. If it was your end desire, it might be worth it, but that is not how I see what you want?

Sorry to be the bearer of bad news - Cheryl

 

I was waiting for an expert on the subject to reply, but I was thinking there is no way to get that motor to work without a complete drivetrain swap. Looks like you are in Phoenix. What part? I'm in the East Valley. Mike Modena (I think he goes by scrappy on this board) is in Scottsdale and may be able to help you locate a donor motor since he does a lot with Nailheads. He is a great guy. I put his website below which has his contact info. Hit him up and see if he knows of a running '64-'66 401. I know that Mike Tomaszewski recently picked up a 401. Not sure what year or what his plans are, but I'll ask him when I see him later today.