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Laux's (Bruno Closs) 55 DeSoto Diplomat Convertible  

Bruno Closs
Active Member

Hey everybody! I'm pleased to join the club!

What brings me to the club is actually a friend's car, a 1955 DeSoto Diplomat convertible (as far as I could identify it). Since the car's owner and myself are quite new to the brand, I decided to start researching for a club, and here am I.

Mr. Laux, owner of the car and myself we are Brazilians. Unfortunately, Mr. Laux does not speak English, so I'm here as a enthusiast, helper and translator.

The car itself is located in the South of Brazil. There is no much info regarding the history of the cars, except that it actually came a few years ago from Uruguay.

Since we are all new to the brand and the car, I would like your help to properly identify the car, model, year and so. Any other valuable information about it, that you are willing to share please feel free to share.

The idea is to restore it. Due to particularities of the Brazilian to register the vehicle and get a plate, we must make it run. It came equipped with a V8, and a automatic trans. I welcome any sort of info regarding the engine, since we must rebuild it soon.

I hope you gentleman's enjoy the project!

Thanks a lot for the opportunity at the club!

Best regards,

Bruno Closs

Posted : 26/02/2018 2:58 pm
Member Admin

Welcome to the world of DeSoto!

There's a lot of knowledge here, and we have a member named Lee Exline that is super-knowledgeable about the export models like your friend's car. I'm sure he'll be along to chime in!

It's supposed to be fun!
1949 De Soto Custom Convertible (project)

Posted : 26/02/2018 3:37 pm
Trusted Member

Yes indeed. 1955 Desoto Diplomat Convertible more than likely built in Detroit on the Plymouth assembly line. there should be a tag on the fire wall that says "made in the USA" You have a export specific model that is mostly a 1955 Plymouth Belvedere but it will be a SP27 instead of a P27 with the S signifying that it is a Desoto Diplomat.

The engine should be a 241CI if it has a 2 barrel carburetor or it could be a 259 if it has a 4 barrel carburetor what are the engine numbers on the block and I can tell you for sure
the grille is export market specific so it is a good thing that you have it and it appears in good condition.

Posted : 27/02/2018 2:25 am
Bruno Closs
Active Member

First of all, you're right Tim! LeeExlin is indeed an encyclopedia! Very clarifying infos!

Th export only models makes sense, since I could find only in France some brochures of the car. At the same time, good that it is basically the same car as the Belvedere, makes easier to find parts I believe, right?

You guys have any suggestion were to source parts for it?

On the front face of the engine block, I found the following numbers: 1737629 A1. Also, in one of the engine head's it has the following number: 1944705-4 (seems those foundry numbers).

Since we have zero literature about the car, I found on the internet a ''1955 Plymouth Desoto Dodge Passenger Car Service Shop Manual'' it includes the following models:
- Plymouth: P-26--P-27
- DeSoto: SP-26--SP-27
- Dodge: D-54--D-59

Do you believe it is worth it to buy?

I will look for the tag on the firewall as well.

Thanks a lot!

Posted : 27/02/2018 8:11 am
Trusted Member

Here is just a small list of export markets that were known to have dealerships.
London, England
Paris, France
Guayaquil, Ecuador
Montevidio, Uruguay
Copenhagen, Denmark
Tripoli, Libya
Tokyo, Japan
Mozambique, Africa
Uganda, Africa
Brussels, Belgium
Havana, Cuba
San Juan, Puerto Rico
Rio De Janeiro, Brazil
Bogota, Columbia
Pasay City, Philippines
Djakarta, Indonesia
Morocco, Africa
Vienna, Austria
Glasgow, Scotland
Lima, Peru
Nykoping, Sweden
Saigon, Indo-China
Dominican Republic
Netherlands Antilles
Ensamblaje and Caracas, Venezuela
Honolulu Hawaii (not a state till 59)
Hong Kong
Panama City, Panama
Belgrade, Yugoslavia
Rotterdam, Holland

Posted : 28/02/2018 3:23 am
Trusted Member

The engine numbers you listed appear to be casting numbers. You are looking for numbers that have been stamped into the engine block. The manual that lists SP26 and SP27 is the manual you want. Depending what parts you need depends on where you need to go. Many of the engine and brake parts are available from well stocked auto parts suppliers (at least here in the states) make sure to look for Plymouth parts.

Posted : 28/02/2018 3:29 am
Trusted Member

The engine may have been replaced?
1737629 is a casting number for a 1958-61 361 engine block
1944705 is a casting number for a 1958-61 head for a 361 engine.
if you have an automatic transmission it should be a Powerflite 2 speed and controlled with a lever on the dash on the right side of the steering wheel

Posted : 28/02/2018 3:40 am
Reputable Member

Welcome to the club..........what a wonderful car you guys have to enjoy. From the pictures, it looks to be in great shape - even still has the convertible boot (the cover that goes over the top when it's down).

Please keep us posted with your activities with the car and feel free to request information. Wish you could be here in Branson, MO for the 2018 NDC National in August.

"It's delightful, it's delovely, it's DeSoto"

"It's delightful, it's delovely, it's DeSoto"

Posted : 28/02/2018 11:28 pm
Bruno Closs
Active Member


LeeExline: Thank you very much for all the information. I will double check where is the correct stamped engine number. I have really not much idea if the engine was replaced or not(there where no 360's on the DeSoto line?). Might be the case, given the car is coming from Uruguay and that is very common there to swap engines. The transmission is indeed automatic and do have the lever just beside the steering wheel. I will order now the manual with the SP26 and SP27 models, thanks for the confirmation. As a first impression, Plymouth parts seems to be easier to find.

FredRoman: Thanks for the warm welcome. Honestly we are very much impressed with the condition of the car. All trims, buttons and details are still on the car. The body do have some rust, but it is minor compared to what we should expect from a car this old down here in South America. We also would like to be in the US, maybe later this year we might go! Let's see!

Does anyone have any idea about production numbers of this exact car?

Posted : 01/03/2018 6:41 am
Trusted Member

The B block engines did not come out till 1958 and the Desoto line had the 350 in 1958 and 361 displacements in later years. Yes Plymouth parts are easier to get than Desoto parts because so many more were made.
I will include an image on where to find the stamped in number you will need to identify what your motor came out of.

Posted : 02/03/2018 11:41 am
Bruno Closs
Active Member


Thanks for the image with the number locations.

The number we found is 251 334 95

I also asked my friend to check the VIN number plate, and it is the same as the engine, I found it very curious, but could it be possible?

I'm curious to understand about this engine installed in the car.

Posted : 02/03/2018 5:46 pm
Prominent Member

https://www.ebay.com/itm/OLD-LARGE-HIST ... SwJ7RYXKWd

Posted : 03/03/2018 2:56 am
Trusted Member

Those numbers do not make sense. Please post some photos of the engine and the stamped numbers when you get a chance.

Posted : 10/03/2018 3:21 pm
Bruno Closs
Active Member

Ok, I will look for it. I'm currently travelling, will take some time to be able to post.

Thanks a lot

Posted : 10/03/2018 7:24 pm


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