Hot Rods what kind of Big Block Chev do I have?

I recently bought a project and I am having a heck of a time decoding the stamped number on the block

The block casting number on the back of the engine drivers side is 3963512 which comes up as a 1969 427 or a 1970-75 454 but the stamped number on the front of the block passenger side is T07247BG and that doesn't seem to jive with anything I have found on any online decoders? especially the 7BG suffix code ? all the numbers are in plain sight and clear as day.

any ideas?

The engine is in a '28 Ford of all things and also has aluminum heads, casting number: 3946074 which came on high horse 427's like L88's
and a factory GM aluminum manifold 3933163 which is from the same era.
I don't know much about big block Chevs, and am just going by what I have found on line.

 

If its a 454, the flywheel and damper will have external balance lugs. 427 is internal balanced. Is there a block date code? If '70 or newer, possible 454. One site shows possible 69-71 as a 427, and 70-76 as a 454. Same casting #.

 

It's not an LS-7, that had the XCH suffix

I don't know what you have, sounds like it's a pretty good motor though. It would be interesting to see what the casting date is on the back of the block, the heads, and the intake. The heads might have it underneath, mine do. kind of hard to see with them on the block. The casting date on the block should be near the casting number you already found, look for a letter follwed by two to four numbers such as G 22 75 or G 22 5

Is there a second number/letter sequence stamped on the front of the block? if so it might be a partial VIN, if it was an engine that was removed from a vehicle. If it's a crate motor (over the counter) it won't have the partial VIN.

 

also maybe post a picture of the stamped number you found, some of them are not quite what they appear to be, they used some odd shaped number stamps.

 

Sounds like a boat anchor to me. Send it to me and I'll use for my boat, I swear.

 

I have seen some stampings that must have been first block on Monday, or last block on Friday.

Practically needed the Rosetta Stone on a few of them.

Definitely post a picture. As close-up as you can and still be steady and focused.

 

I had one that was double stamped, same numbers overlapped, that was difficult to read. Sold to a guy who thought I stamped it like that

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Well you're right, I can't find anything that makes sense either. The "BG" would indeed be where you'd find what it was used/built as and also in what model car/truck, yet it doesn't appear anywhere in online lists. I tried Canadian just for fun but get the same links. Running out of time, I didn't try to find tall deck stuff. Big block fans can tell just by looking if it's a tall deck, but I doubt that due to the casting #. Late 427 to early 454 seems logical but what flavor? Don't remove the idea that it could be from 1970, or in fact 46 years old (!) and could be anything now. Might even have a stroker kit in it and be a 496, might be a leftover service part with a different code than normal (Canada?), but the T in the TO confirms it as a "Tonnawanda" plant build and little else. I have some books I can check vs limited 'net knowledge but I'm in a scramble against the clock on multiple issues/builds at the moment.

 

As I recall back from my days with them, the 4 bolt main blocks had oil cooler in and out bosses with plugs right above the oil filter. 2 bolts did not. I have a '73 454 2 bolt block and it does not, my '60s 427 4 bolt block did.

 

If you cant find your suffix stamping in the published lists, you have an over the counter engine, most likely a warranty replacement but it could have been bought "over the counter" by a hot rodder. I have 2 of them, 302's that according to the published lists were never made.

 

All of the early 454 BBC blocks I've seen have 3 letter suffix codes like CRT etc, exception would be a crate motor I suppose, if the casting date isn't on the back look on the pass side by the pan rail for it

 

Most 454s I see are truck motors, the 70s versions usually have a 3 letter suffix starting with T.

 

It's a 427 with square port aluminum heads...does anything else really matter after that?

 

Not really....

 

Its probably a marine specific code...I've had a few of those over the years...found a post online where a guy wanted to know what 427 with "2CW" code meant...it was a reverse rotating 427 390 horse engine intended to be used in pairs....so pretty sure 7BG is a marine code...

 

sure, but it doesn't show up in the MARINE list

http://www.chevy-camaro.com/chevy-camaro-chevy-bb-engine-suffix-codes.asp?group=12

maybe it's too old?

 

Jim....it doesnt show up on the lists we see because it is not a car or truck specific code. All the lists we see are Camaro..Chevelle...Impala....Truck...etc. Over the years I've tried to find lists of marine codes without luck. That 2CW code I referenced was only sold through a certain outfit...maybe GM was making engines to spec for marine use.

 

Wouldn't that be a big surprise to drop it in, get it running and put it in gear... And go the wrong direction!


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uh...did you actually look at the list I linked to? It's a marine engine code list! just what you are looking for.

 

Jim...lol...I did now. That's a great list....THANKS! The wording in the link implies it's the same ole same ole list. Never found a marine list online...but never really tried super hard. Last marine LS6 I had was several years ago...pre smart phones...

 

It was really difficult to find that list....go to google...type in chevy marine suffix code

 

If it's not in the Marine list try the Army.







Sorry, couldn't help myself ya know?

 

Maybe these guys will know???

 

What kind of big block chevy do you have?...........a bad ass one

 

Thanks for all the help guys ! I can't get pics to post (I'm pretty compu-retarded) The engine is still all together and in the car so pictures of the block casting numbers are pretty much impossible, the only way I got the numbers off of it was with a mirror and flashlight. The Heads and intake are probably from different engines, who knows? it has an aftermarket balancer and a aftermarket front distributor conversion. The Car was built in the late 1990's and I don't know much about it. The Aluminum heads have been fully polished on the outside ! The stamped number on the block is not double stamped and the number is clear as a bell and easy to read. The Roadster is a pretty standard 80's-90's build 16" wide goodyears on Centerlines on a chromed-out Vette rear, full fendered with a rumble seat and bumbers ! at least the front is still a dropped beam (with 4-bar of coarse)

 

Damn, I guess I hate u just a little more with that description. Sounds like someone went all the way with it. I like BBCs as much as I like Packards.

 

Some pics for the OP. Car has that 'charm' of the 80s IMO but what a great start

 

Pull the fender, change wheels and tires, maybe hood sides and call it done. In case you were looking for opinions??

I've got a 454 marine, I'll post the numbers and pic in a week when I'm at that shop. Very cool block, has 4 bolt mains on the front and rear, not just the middle caps. I'll do a 496 with it eventually.

 

like every other BBC with 4 bolt mains....only the small blocks have 2 bolts at the front and back mains. The small block was designed as a 2 bolt main motor, the big block was designed as a 4 bolt main motor.

My guess is, the car could move pretty good with that mill.

 

Uh yea, 8.20-16 bias plys are JUST what that car needs...