Need Help decoding my Plate 1951 Roadmaster

[V1CT0R]

I need help decoding my ID Plate of my 1951 Buick Roadmaster.

1951 MOD 51-72

STYLE No 51-4713

BODY No G 866

TRIM No 72

PAINT No 13/BD

TOP ACC

My son just gave this to me and it is in good shape. Is this a Riviera ? The Vin number doesn't make sense either and is ,listed next.

16I88887

The last is the number off of the manifold.

1288765

Thank you for any help, I am new at this.

Vic McDonald

[Bill Stoneberg]

Hi Victor,

Nice present from your Son. Welcome to the world of Buick.

It could be a Riviera but my books show it a Model 51-72R with a body style of 51-4719. Maybe this is just a 6 passenger sedan ? My books are lacking on this one.

Trim looks like it should be a Dark Blue Broadcloth with a Light Blue Broadcloth insert.

The paint is two-tone.. Syk Grey on the upper and Victoria Marron on the bottom. Wheels are also the maroon color with 3 silver stripes.

Serial numbers for cars buuilt in flint were from 16740001 to 17214106 so maybe that I is a 7 ?

What kind of shape is the car in ?

[Guest imported_Thriller]

Bill is right about it being a sedan. In '52, they are referred to as a Riviera sedan, but the Riviera name generally referred to a hardtop.

You may want to check out Buicks.net '51 page for additional details, paint codes / chips, etc.

Good luck with it.

[V1CT0R]

It is in grat shape! I have lots of photos and it's in great shape with a maroone body 4 portals and a eggshell top. It has a Dynaflow transmission. Thanks for your help.

Vic

[B.Goode]

Hi Victor

Your car is almost the same as mine, mine is a 52 Roadmaster Riviera, 4 door 6 passenger sedan, and it was called a Riviera in 1951 also !

Bill Stoneberg is right on the money with the information, except in my books the serialnumbers for cars built in Flint starts at 16031301, so that "I" would probably be a "1".

Does your car have the hydraulic windowlifts ? The stylenumber should read 51-4719 and with a "X" suffix if it does have the Hydraulic Windowlifts and no "X" if it doesn't !

[V1CT0R]

The serial number is the cofusing part. It is definately an I "16I88887" no doubt.

HMM

thanks again

Vic

[V1CT0R]

I did got to the for mentioned Web site and my ID Plate doesn't have a "R" just 51-72 and is a hard top.

Vic

[V1CT0R]

It is an I have attached a picture of the ID.

Vic

[B.Goode]

I hope your ID plate doesn't have an "R" that would make it even more confusing !!! If it has an "X" after STYLE NO 51-4713 it would indicate hydraulics.

According to your IDplate you have a 4 door sedan bodystyle 72, if you car is a hardtop it would be a 2 door bodystyle 76R (or 76MR) it cant be both the 4 door hardtop wasn't available til 1955 !

If you do have a 4 door hardtop from 1951, I would love to see pictures of it.... Arrhm I would love to see 'em anyways

Uh and darn it, you are of course right about the number on your serialnumber plate, now thats a bit strange !!

[V1CT0R]

I sent you some pictures of it.

Vic

[Bill Stoneberg]

How about posting one here so we can all see it ?

Thanks

Bill

[V1CT0R]

I tried but the file is to big.!!!

Vic

[V1CT0R]

OK, I shrunk it and it is in the photo gallery!!

Vic

[Centurion]

Victor, I'm taking the liberty of linking your photos here.

While a side photo would be helpful, the car does indeed appear to be the "Riviera Sedan", which was the name that much of the literature applies to this particular model. The "Riviera" style referred to a pillarless hardtop style on the 2-door hardtops, but a pillarless 4-door hardtop did not appear until 1955 (small series) and 1956 (big series). During this timeframe (early 1950's), the Riviera Sedan was a "six-window" style 4-door sedan with centerpost and door frames around the windows.

[B.Goode]

Thanx for the pictures you send me, Victor.

With some imagination, it is possible to mistake the last number in Style no. 51-4719 as a "3" but in the bigger file that you send me, I would say it looks like a "9". Which makes the numbering correct for a Rivera sedan.

From the pictures it looks like the original colors, is it the original paint ?

It must have been a striking car when new, that dark red color, and all that bright chrome and stainless, absolutely gorgeous !

[V1CT0R]

Thanks to all for the help. I am still puzzled on the VIN number though. It doesn't make sense to me.

Vic

[Guest sixpack2639]

I'm not sure what the deal is with the "I" in the body vin number but my '51 Special has one too. Mine is 76083I97. I also thought it was meant to be a "1" at first but now that i've seen yours and there is a "1" in your vin i'm at a loss. I just had a fellow in Canada decode my build sheet and sent him the info off the spec. plate with the build sheet but I didn't send him the body vin so I will have to contact him and see if he has any insite into this. Carl

[V1CT0R]

Thank you so much!

I love this car with 36K original miles.

Vic

[Glassesguy]

Victor& Sixpack:

Since the letter "I" has shown up in the body of both your serial numbers, I wonder if a decision was made to use that letter character instead of the numeral "1" when the numeral "1" was needed in the 7 digit serial number. The actual numeral "1" would then reserved for use only as a prefix to designate the assembly plant. My parts books don't show anything about this. Maybe someone with a 51 Shop Manual or Service Bulletins can find it in there. Let's really go outside the box and speculate that perhaps there was only one numeral"1" die available for stamping the serial number plates, so somebody hit on the idea to use the capital letter "I" in the body of the serial number. Make sense?? According to Terry Dunham and Larry Gustin in their book "The Buick, A Complete History " Harlow Curtice was such a thorough cost cutter that he ordered "all nuts be reduced a by a few thousandths of an inch to save a fraction of a cent a car". (page 248 of the first editon). Why make 2 dies of the same character when an existing piece can be adapted? Extreme?? You decide.

[Guest sixpack2639]

Glassesguy, No offense but you must need to clean yours. Go back to the top of the thread and look at the pic V1ctor posted of his body VIN. It has both a "1" and an "I" in it and mine only has an "I" so that nixes your theory. I have a '51 Shop Manual and service bulletins and there is nothing in them that refers to the numbers or letters used in the body VIN. Carl

[Glassesguy]

Carl:

Victor's car was built in Flint as indicated by the "1" which starts his VIN number and as verified by by the letter "G" on his body plate. Your Special starts with the numeral "7" which indicates it was built in Framingham, Mass. Your body plate may possibly have the letters "BF" on it to verify this as these letters were used to identify Framingham as the build source. All 51's used an 8 digit serial number with the first digit indicating where the car was built.

"1" Flint; "2" South Gate; "3" Linden; "4" Kansas City; "5" Wilmington; "6" Atlanta; "7" Framingham. The next 7 digits were for the serial number done in sequence. Flint Built cars started with VIN number 16031301 so according to my post and theory, both the numeral "1" and the letter "I" could appear. Your VIN would CONFIRM my theory as Framingham cars started with VIN number 76080001. It would be interesting to see if anyone had a VIN with two letter "I"s appearing in the last 7 digits of the serial number, paricularly one of a Flint built car. That would seem to be even more convincing that the letter "I" was used in place of the numeral"1" only in the last seven digits of the eight digit VIN. Personally, I would have thought it would be the other way around, but we know Buick had some kind of reason to do it this way. My source for these codes is the 1936 to 1958 Buick Master Body Parts Book. My Service Bulletin collection unfortunately skips 1951, so I'm glad you confirmed that this info is not in either the Shop Manual or Bulletins.

[Guest sixpack2639]

Ok Dave, I stand corrected. When you put it that way I can see your theory has some merit and I would have to agree with you. I spoke with the fellow who decoded my build sheet and he too believes you may be correct as he has no other explanation for the "I" in the body VIN. In response to your statement that my car was built in the Framingham plant, you are correct. My Body# is BF652. Carl

[V1CT0R]

The body has stamped in it "F06 4569" but my ID plate clearly says Flint. Hmm, sounds good.

Thanks again

Vic

[Guest sixpack2639]

V1ctor, The Buick Motor Division, General Motors Corporation, Flint, Mich. on your body plate is on all body plates reguardless of manufacturing plant. Your body# is G866. The G is the designation for the Flint plant as Dave said in his reply above and the 866 is the sequential # of that style body made for the year. Carl

[Guest DaveCorbin]

To all the guys on this thread:

The subject of Buick's frame number system has mystified many people for years. Here's how Buick did it from 1937 thru 1953: At the start of a year, each plant is assigned a block of frame numbers that do not overlap each other and are sequential and are sufficient for about 3 months of production in the production/forecast plan. These blocks are ALWAYS assigned in order by the PLANT NUMBER. In other words, Flint gets the first block of frame numbers (1), Southgate is always next (2), Linden is always next (3) and so on in the order in which the plants came into the production process over the years. About a month before everyone will run out of frame numbers, a new round of assignments is made, but the assignment sequence of Flint, Southgate, Linden, etc. is ALWAYS followed. This assures that there are no duplicated frame numbers and, if you subtract this years starting frame number from the next years starting frame number, you will normally get (within a few cars) the number of cars produced that year. The one year in the postwar era where that's not true is 1949, where Buick left over about 11,000 frame numbers unused, all at Flint. This is because they started building 1950 Specials in June 1949 and were still building 1949's on that (1949)frame number sequence. As a consequence they guessed how many 1949's they were going to produce in the 6 month period and knew that the guess HAD to be LONG and started the 1950 frame number sequence at the end of their "guesstimate". (You would not believe what they did in the 1918-1925 time period. Suffice to say that sequential frame numbers can be for the prior model year in those years and let it go at that, making some real messes for Dave Chambers, Terry Dunham, and I to unravel years later!!) I hope this helps shed some light on the subject of Buick's methods. It may look like madness, but there really was a systematic way of doing it!

Regards, Dave Corbin

[Pete O]

V1CTOR,

Beautiful car! I see from the picture that you're missing the left side moustache bar end piece. I have an extra that I took off my 1951 56C that I think will fit (I believe the front end pieces interchange on the 50 and 70 series cars). It's got a bit of a dent in it, and the chrome is moderately pitted, but you can have it if you want it for the cost of mailing it to you.

Pete

[Budd]

Dave:

Thank you for that explanation! Does anyone know how it worked after 1953, ie. 1956 ? I can make sense of the body plates, but the VIN has the last 6 digits that I have not seen how to decode fully, except mention that the last 6 are split into (3) production number and (3) sequence number,

ie. 5C2045464

5 = Series 50 Super

C = 1956 Model Year

2 = Southgate, CA Factory

045 = Production Number

464 = Sequence Number

I guess I'm looking for something like "it was built in April and was the XXX off the assembly line" or similiar.

Cheers,

Budd

[Guest DaveCorbin]

Dear Budd:

My understanding of the fourth Buick numbering system as used in 1956 is as follows: The first digit indicates the model series, 4=Special, 5=Super, 6=Century,7=Roadmaster. That's followed by a year code digit as follows: A=1954, B=1955, C=1956, D=1957, E=1958. The third digit is a plant code as follows: 1=Flint, 2=Southgate, 3=Linden, 4=KC, 5=Wilmington, 6=Atlanta, 7=Framingham, 8=Arlington. This is then followed by a 6 digit sequence number that always starts with 001001 for the first car, followed by 001002 assigned to the second car, etc.

You are correct that a serial number starting 5 (Super)C(1956)2(Southgate)045464(45464-1000=44,464th car at Southgate in 1956 model year) is the way to decode this thing.

I'm currently thru 1950 on compiling a complete 1904 thru 1958 Buick frame and engine number cross reference by month by plant. That's a little over 9 1/2 million cars and already is a databse list more than 160 pages long, consisting of about 3750 lines of information so far.

Have patience with me as I've spent 5 years at about 1000 hours per year to get this far.

The prevailing wisdom has been that Buick threw all this info away about 40-45

years ago, but people like Dave Chambers, George Damman and especially Terry Dunham and Larry Gustin saved enough to enable a (Patient? Persistent? Tenacious? Wife claims Idiot?) researcher to put it back together again and even correct Buick's typographical errors!

The part above is the EASY part! The first VIN system from 1904-1914 was so different that it took about 2 years to figure it out. The second, used from 1915 thru 1931, is very cumbersome, but has an enormous amont of usable information. The third from 1932 thru 1936 is straight formard but doesn't give you a lot of info, and it's derivative system , used from 1937-1953 is a nearly impossible thing to follow logically, especially as more plants come into the system. (See the article by Terry Dunham and I in the Bugle late in 2002 as an example). What I'm doing is translating all 4 systems into the same format so that the when, where, what engine number went with this frame number(VIN), questions can be readily answered. Like I said "Have patience with me!" Oh yeah, in order to get the engines right, I'm having to do McLaughlin/GM of Canada, TOO!!!

I hope this answers your question about the '56.

Regards, Dave Corbin

[Budd]

Dave:

Thank you for that informative reply! My hat is off to you, you must be the kind of guy that sits down with a 5000 piece puzzle at Christmas time and look up from the kitchen table 12 hours later when it's complete I would have hoped that more information could be derived from the post-1953 numbering system, ie build month. Perhaps you could guestimate that from those recent production sheets that were on eBay (autolit). They listed out the number of each vehicle type produced, from each plant, from 10/1955 - 9/1956-- which I would assume is the 1956 production year. I suppose if you did the math, you could approximate the build month of the vehicle based off of total numbers producted to date, compared to your vehicle number as you described.

Budd