442much

So I've pulled my 455 out of the car for a rebuild. There are a couple of spots where I see numbers and letters but am not sure what they mean. There is an "F" about 3" long on the passenger side of the block down by the manifolds...don't know what that means. Near the distributor "hole" there is an "8" and just below that it says "240". Any idea what these mean?

GreekDog

the "f" is for Ford right? :P

just kidding! Im not sure but Im sure someone here will know.

442much

I thought it stood for "Fast."

don71

Just guessing here....The 8 would be a mold number. The 240 would be the 240th day of the year. Are there two little "screw heads" to the left and right of the 240? If so, I think thats it.

BlackGold

Yup on both numbers.

442much

"screw heads" are there. Thanks.

bobb

Ken,

Brian may disagree on this one, but someone on this forum pointed out that the "Mold Number" is correlatable to year the block was cast. I've check his system or idea on all the 455 blocks I've come across since I heard this a few months back.....and every one has fit, including my own. The way it works is a Mold number of 3 = 1969, 4 = 1970, 5 = 1971, 6 = 1972, 7 = 1973, 8= 1974, etc, but I don't know how high they go, I've only seen 3 thru 8 so far. Also only works for 455 blocks. Might be shear coincidence.......but I'm a believer until someone proves the system wrong. Just my 2 cents to ponder.

later,
bob

Allan R

Hmmm, Ken. I didn't know you had a 74 455 in your 76 442. Did that puppy get swapped out on you when you weren't looking???? Either that or the Mold numbering system may have met it's first fly in the ointment...

FWIW I also have that big F on the 455 you sold me last year. Couldn't find the 'mold' number or date of build. Have to look in the daylight. The dist is still in so maybe I'll have to take it out to find those numbers?

I did notice that the F below the manifolds is styled the same as the F on the top of the intake that identifies the BB. Maybe they are matched that way?

Anyone know what the letter would be on a 400 or 425 block?

young olds

My 455 says 44, i would like to know if that is the 44th day of 67 or 68? I know the new model year is produced before that year actually starts. My car is a 68 and the protection plan book says it was first put into service 3/29/68.

442much

Allan, I doubt it's a 74 block and it is a 455. The serial number on my car starts 3G37T6M------ the "T" signifying a 455. The number just behind the water pump .....
DSC_6640.jpg

12 Years after I bought the car I met the original owner. I had noticed just before meet the original owner again, that the serial number tag on the block did not have my serial number on it. Did the dealer do a "Yenko" on this car? So I asked him if he changed out the engine in the 2.5 years he owned the car or had the dealer done something. He said that he did not replace the engine. He did recall that the car had a crank problem about three months after he bought it. He took it in under warranty and in a couple of days they called him to come and get his car.

DSC_6641.jpg

The number above reads 5435. I suspect that they swapped out the original short block and happened to have a 68-72 455 block lying around and used that...unless they ground off my serial number and stamped this number on it to show it had been rebuilt. Could they have rebuilt it in two days and would the dealership do that? Perhaps this is a dealer replacement block. What confuses me is by 1976 you'd think that all 396021F blocks were long gone and any replacements would have been 396021FA. Ever since I've had the car, I could fry the tires on it.

I remember in Calgary the first summer I owned the car I went up against a 1969 440 Roadrunner in a street race on 9th Ave. I swear to God, I beat that guy and I heard him say to his friend in the passenger seat "I guess we have some work to do on this car." She was always a fast car since day 1, but the block can't account for that, so I don't know.

On to the original question - here is what I was talking about. You can just see the "8" and the "240" underneath. Just wondering what it meant. I guessed that the 240 was number of the day in the year the block could have been cast, but that would have been Thursday Aug 28, 1975. My car was assembled on March 1, 1976. If the engine was cast in Aug 1975, then why is it an "F" block and not an "FA" block? Of course it could have been cast in Aug 1971 I suppose.

DSC_6599.jpg

Allan, the block I sold you has a 1973 serial number on it and 1973 parts, even J heads. However you'll notice that yours is an "F" block too. All the literature I've found says that "F" blocks are 1968-72 455's and "FA" blocks are 1972-1976 455's. I know nothing is written in stone, but I've never seen one book that says otherwise.

I was just curious on the "8" and "240". Still not sure what a mold number means unless this is a 1974 "F" engine which just doesn't jive.

442much

Then I'm guessing your engine was cast on Tuesday February 13 1968, the 44th day of the year.

bobb

Allan....... I'm not seeing the fly just yet. The VIN-derivative stamped on Ken's block shows that's not the original motor to his car.....VIN-derivatives are not 4 digits. It's been documented on this forum in some threads I started early in this year that F blocks (not Fa) were produced and installed by the factory in Oldsmobiles well beyond 1972, despite what the books say. So using the Fa and F to distinguish years won't work beyond 1971, as both were used thru 1976 I believe.

To me it looks like the block in the picture was made on the 240th day of 1974, which was August 28th. So far no fly in the ointment. No matter what year, the block casting date and the car assembly date don't match up. It's not the original block. I'm betting that when you check the 73 motor that Ken sold you you'll find the Mold number to be either a 6 (if the block was cast in the fall/winter of 1972 for the 73 model year, or a 7 if the block was cast after Jan 1, 1973.

It's tight back there but with a good flashlight you can see the Mold and Julian numbers without pulling the distributor. One of those little extending mirrors also works wonders. Guess we'll tune in tomorrow, same Bat Time, same Bat Channel to see if find that fly.

take care,
bob

442much

I didn't think it was 76 455 but I never thought it was a 74! I thought it was a 68-72 block. Can't believe everything you read I guess. Every book I own or have seen would state that the "F" identifies it as a 68-72 block. I guess the dealer pulled a "Yenko" by replacing the engine. Thanks for clearing this up. If it is a 74 455, they called them W30's in Hurst cars.......Now I'm starting to wonder if a hamburger is really made from ham.....

507OLDS

Not all of the 73-76 455 blocks were Fa blocks.I have had some that were not,but the Fa block was introduced or used in that time span(73-76). I'm still sure that your block was cast on the 240th day of the 8th year of production,or the 240th day of 1974.Regardless,it's not the original block to the car.Not sure if it was a warranty replacement,or some other dealer/service engine.Check the dates on your heads,and compare them with the block.That might tell you if they swapped the whole engine,or just the shortblock.
Another thing with the "8",or whatever number you might have next to the distributor hole: If you look on the underside of the oil filter pad,on the block,you will find the same number,so your block will have another "8" down there.Just something else I noticed.

Allan R

HOLY LUMPY CAMSHAFTS BATMAN!! Will our caped crusader be able to distinguish the difference between built up grime and numbers? We tune in today to find out......

Yes, The numbers on my 455 show it as a 7 casting with 173 as the day. That should be June 22, 1973? FYI, I still have the motor on an engine stand so it wasn't too hard to get in and find the number. The stamping on the engine block shows the serial number is 33M123193. I'm not sure what the 33 means but I'm guess 3 = Olds 3M = production year and Lansing production. The last 6 are the blocks serial number

So, do you have an RO from the dealer showing the work or is it probably lost forever? What made you think it wasn't a 76 block to start with? I'm shocked your car isn't #'s matching. BTW you can still call it a hamburger. It would just sound stupid to call it a ground cow meat burger

Well I double checked. My block is definitely an F block, not Fa even though it would have been cast in mid 73. The markings were just as you described. It was hard to get under the oil fllter pad, but it appears to have a 7 cast there too.

Q: Yes I have J heads, but that' ok for what I want. What are the letters and numbers cast into the head above each exhaust port? Both heads have the same numbering: CFD -- 411 -- 783 -- 221. On the even cylinders the numbering starts at #2. On odd numbering starts at #7. edit: only thing that makes sense to me is that they were a matched set from the factory?

507OLDS

The 33M stamped in your block translates to:
3 = Oldsmobile
3 = year,1973
M = plant,Lansing Michigan

Allan R

Thanks Brian,
Do you have any idea what the casting numbers/letters on the heads mean?

bobb

Allan,

The numbers on the head are the casting numbers (411783) and the Julian date code (221st day of the year). I don't know what CFD stands for but would summize it was the casting house name abbreviation.

Just to give credit where it's due.....Brian is the one who figured out how the Mold number equates to the year the block was built. Kudos to you Brian.

later,
bob

442much

What made me doubt it being a 76 engine was the 396021F and not the FA. Everything I read said the F blocks were 1968-72. So I knew there was a change in the first two years of the cars life (I bought the car before the original had it three years and I knew that I didn't change anything). I learned what the numbers meant (or were supposed to mean in 1990). I happend to meet the original owner in the summer of 1990 when I was living in Jasper National Park and he happened by in a van and stopped to see the car. He didn't know it was his car originally. I bought the car off him in Calgary in spring 1979.

I contacted the dealer by snail mail (people didn't have email at the time). The owner of the dealership (was also the salesman who ordered my car) called me back. He said that he remembered the car as it was the only 455 ordered in a 442 that his dealership sold that year. He said that he had closed the dealership after his wife took sick and just that month, sold the building to a food chain.

He said they removed hundreds of boxes out of the dealership and to a storage facility pending destruction. I asked if he had any bills, or invoices that I could have pertaining to my car. He said that if he came across anything, that he would send it to me. So no, I don't have anything in writing which is too bad. I suppose I could always grind the four numbers off and stamp my serial number number on there. Will I? No. What's the point? 1. Do I want to sell it and decieve someone...I don't. 2. This year of 442 although rare, will never bring $150,000 at Barrett-Jackson in my lifetime and is not as popular as the 68-72 (and that what I like about it). I like the 68-72's but you see them everywhere, this one you don't. 2200 cars at the 100th Anniversary and mine was 1 of 2 there and the only 455 car. and 3. I don't care.

I love the car not for how much I can get for it but for the memories of things I remember about it; bringing my three sons home from the hospital in it, having Oldsmobile pick it to represent its year in Lansing at the 100th anniversary, having driven from Vancouver Island on the Pacific to Cape Cod on the Atlantic and all the great conversations I had with people along the way (this was Karen's first trip east). When I think of this car, I think enjoyment, not investment. I will never sell her (unless some crazy millionaire just has to have her).

The car has 180,000 miles on her, and in my opinion, looks fantastic. I hope to put another 180,000 on her before my time is up and have her look the same as today when one of the boys gets her. She's never been a trailor queen, and she'll never be as long as I own her.

So, when it comes down to it the engine was installed by the dealer. That was something done by many dealers. Why the dealer would use an older block is beyond me, but the original owner ordered a 455 and the dealer returned a 455. The dealer also changed (you've all heard this story before) the intake to the 71 aluminum, 3:42 posi and the dual gate shifter. When I spoke with the dealer in 1988 I was actually looking for invoices for this work as I didn't know about the crank problem until two years after. I never did hear from the dealer and heard he died about three years ago. So I'm SOL on that. C'est la vie.

Allan R

Soooo, if a hamburger is made from beef and no one questions it, why would anyone want to question your car? I don't ever remember hearing you misrepresent it, and it's really obvious how proud of the car you are. Personally, I also love the way your car looks. I enjoyed sitting in it last summer (almost as much as I enjoy my own). I guess it just comes down to the fact that we'll keep on finding out neat things about our cars as we continue to do neat things to them. I guess George at GM Vintage services wouldn't be able to provide any information about how the 'swap' process at GM dealers may have been authorized?

How's the build coming along? Got any pics? I'm starting to plan for the work I want to do on my 72 this year. Won't all be done by July though. You got the weather set for RR yet?

442much

The weather has been ordered. If I get someone who asks me at a car show if the engine is original and they want to stop and talk, I tell them the crank story. If they ask while moving on to the next car I just say "yes".

I've got the pictures over at the 73-77 forum. As I said, these cars aren't as popular as the 68-72's and I noticed the thread died quickly so I went over to the 73-77 and it's going pretty good...as long as I update the pictures. The heads are being rebuilt and the block is being honed. There will be more pictures and updates after May 7 when the builder gets back from Hawaii. Are you going to the show this year?

Allan R

Ummmm, I guess you musta forgot. Couple of months back I offered to help you set it up and take stuff down. So I guess the short answer would be yes. Still time between now and then, but LMK if you want to get together and discuss your plans for the roundup this year. You have my ph and email from the club roster + I know where ya live. Beware of Olds pedlars selling Coke door to door.

PS: What do you call an Irishman selling lawnchairs door to door??

Paddy O'furniture

442much

One thing I'm confused about. The 455 was only produced for passenger cars for 9 years. The 8th year of production would be 1975. 1968 being the 1st, 69 2nd, 70 3rd, 71 4th, 72 5th, 73 6th, 74 7th, 75 8th, and 76 being 9th. Why wouldn't "8" represent a 1975 build date?

I have read in muscle car mags (not that they're right) that some components could be built 6-7 months before a car was assembled. If that is the case, this engine would be the correct year for mine although still not original. I wonder why a dealer would use a 1.5 year old engine rather than a newer one. The build date on my car is 02D. The 1976 cars could have started being produced in August of 75 and "8" "240" could be August 28 1975 and not 1974. Thoughts?

If the "8" represents the the 8th year of 455 production, then it's possible that this could be the original block. Is it possible that the original serial numbers were ground off to show a work order number? Stranger things have happened. All this time I thought this engine was a dealer install, no doubt...now I'm not so sure.

bobb

Ken, I'm sure Brian has the real answer, but I'll take a stab at it. If they started putting 455's in cars in the 1968 model year they would have had to start casting the blocks in 1967, as the 68 model year started in September(?) of 1967. That would make the Mold # for 1967 blocks = 1, 68=2, 69=3, 70=4, etc, etc. That's the best I can pull out of my butt on such short notice. (SMILE)

take care,
bob

Allan R

bobb,
Wow! That's the same thing I was thinking.

442much

Actually that makes sense Bob, and I've got nothing in my butt file. Thanks for the clarification. I just want the truth, whether I like it or not.

507OLDS

Yes,you have that right.They started to cast the 455 blocks in 1967,for the 1968 model year,so 1967 is the 1st year.I used a 455 block like that last year,for a build.It was a 68 455,with a 68 VIN,and had "1" and "332" next to the distributor hole.332nd day of 1967.