I have had this motor for a couple years. I got it for a 55 chevy and I never installed it. I dont think its anything special. I just would like to know what car it came in from the factory. Its a 2 bolt main block that says hi perf/pass. thanks for any help. Mark

engine pad
T0522COW
70S412865

Casting#
3963512

across from casting#
L 15 9

 

3963512 427 68-69 Passenger 385,425 HP
3963512 427 69 Chevelle,Camaro COPO (Central Office Production Order)
3963512 427 69 Corvette Late 69
3963512 454 70 Corvette,Passenger 360,390 HP
3963512 454 70 Chevelle LS-6 450 HP
3963512 454 70-71 Pass,Chevelle, Monte Carlo
3963512 454 71 Corvette 365,425 HP

L 15 9 means December 15, 1969 so it went into a 1970 vehicle which makes it a 454

 

The part which looks strange to me is the sequence number, 70S4(12865) , which would put in about 3/4 through the 70 production year. A block cast Dec 15, 1969 seems too old for a car built that late.

 

ok...I am confused...very...the engine code T0522COW means
T-Tonawanda
05-May
22-22nd
COW-there is NO COW engine suffix...no O follows a C in the engine suffix codes...the only 3 letter code that starts with a C and ends with a W is CTW
Camaro 1970 400cid 8cyl, TH400
Chevelle 1970 396cid 8cyl, TH400

 

I would bet it's A CGW not a COW

CGW = 1970 454 390hp Corvette LS-5

 

I think your are right. I went out to the garage and looked at it again and it could be a G and not a 0. i dont think it was a crisp stamping. thanks everyone for your reply. Mark

 

COW can easilly be mistaken eyeball wize for a CGW

if it is a GCW then it is a 1970 corvette 454 390 horsepower engine block, with Automatic Transmission.
The block was cast on Dec 15, 1969 and assembled over 5 months later on May 22, 1970 in the tonawanda engine plant.
it was shipped to the corvette plant and placed in a corvette number 12865 on approximately June 22, 1970.

according to the numbers this is what you have..

now, it is very fishy that the block sat around the engine plant for over 5 months before being assembled. as a result it is either a very rare exception, or a restamp/forgery/counterfeit stamping, and was . stamped to make a date line up for the corvette that it used to be in.

either way it doesn't matter.. you have a 454 block from that period and they built and put 454s in big chevys, chevelles, trucks, .. and corvettes. doesn't matter to anybody, unless you happen to know where corvette 12865 is...

i had heard that there was a strike in april, 1970 for 4 weeks halting production, so this explains about 1 month of the 5 months. but don't know if the strike halted tonawanda also as well as the corvette production line.

 

\
Here is a shot of the number

 

Stamp looks weird,
File or sanding marks at right angle to broach marks.
Phantom numbers under stamp.
Poor allignment of stamped characters.

Andy

 

yeah i see what your saying. I can kinda see the ghost of what could be another set of numbers. I may take some paint thinner and clean it out. It doesnt really matter cause i dont have the car it came in, I was just curious. The guy i got it from had it in a 4wd Chevy van.

 

the numbers don't line up, you can see a little of the previous stamp under and near the letters, the broach marks stop at the start of the pad. And there is paint on the pad and in the letters which means the engine has been out and painted.. so who knows what was done while it was out.. i would guess it was restamped to match a june 1970 corvette it went in at one time.

it also could possibly be a 427.. you should check the stroke and make sure it is 4.00"

interesting life of the motor. was probably a CE engine or another 454 in another car.. was acquired and restamped and put in a 70 corvette, then sold to a guy that put it in a 4wd van, then sold to you.. thats the minimum, it might have had more owners and been in more cars..

 

Yes definitly interesting life, I have owned it for two years and never thought to decode the pad number. The guy before me had it in the 4wd van for more than 10 years. if I run my finger over the pad I can feel where it was ground down. I cleaned it up with some paint thinner.

 

Great photo work on the phamtom stamp! I think you have started to unravel the mystery

Andy