Mystery engine and tire decoding

[Ed M.]

I have a 1976 454 block, casting # 361959, dated 1/30/76, pad stamped C7F336029, with matching heads, casting # 336781, dated 1/17/76 (270hp???). Is this puppy worth rebuilding as a driver engine, or will the heads take too much work? If it is a stock engine, do you know what the rated horsepower would be?

I know there's a website somewhere that helps decipher tire codes. These tires fit 1979 to 1982 and are Goodyear Polysteel Radials, WRL, P-225 70 R 15. The DOT codes on two tires are F06L MKUU CYE417 and the other two are F07R MKUU CYE407. They are NOS and still have the nubs on the tread. Which year are they correct for?

Ed

[Terry M.]

Re: Mystery engine and tire decoding *TL*

Ed,
Look for an engine assembly stamp on a pad straight above the timing chain cover. I have seen some large motors assembly stamped there during the late 70s. The F in the assembly plant is Flint (CK10-20-30) truck plant, so it was installed in a truck built at Flint.

The dates on the tires are 40 week and 41 week of 19X6. Likely 1976 from your description. I don't know of a web site with the Goodyear codes listed, but it would be nice.

[Joe L.]

Re: Mystery engine and tire decoding

Ed-----

As Terry mentioned, since the VIN-derivative indicates that this engine was originally installed in a truck, that and the cylinder head/block casting numbers which you provided are about all we know about it. If I'm reading the VIN derivative correctly, I'd say that it was a 1977 model year truck which also fits with the block and cylinder head usage. The probable HP rating for the engine was in the 200-240 hp range (1972+ SAE NET horsepower rating system, though).

This engine could be built into a VERY nice driver engine, even with the existing heads. You couldn't make a dragster out of it, but you could make a very nice, high torque street machine. These cylinder heads have 225 cc intake port volume which is the same as that used for many earlier oval port engines. Combustion chamber volume is about 113 cc.

[Duke W.]

Re: Mystery engine and tire decoding

The last digit in the date code corresponds to the last digit of the year of manufacture, so the manufacture dates would be 40th and 41st weeks of 1977 or 1987.

I have a circa '86 GY Eagle Tire catalog and "Polysteel Radial" is not mentioned. Of course, since they are not "Eagles" they may have been listed in another GY catalog, but my hunch is that this tire was out of production before the late eightites, so it was probably manufactured in 1977.

Beginning about 2000 date coding increased to four digits, the last two being the year, so 20 years from now we won't have to guess the decade or determine it by researching the years the tire was in production.

Duke

[Terry M.]

Too early in the morning 77 not 76 *NM* *TL*

[Duke W.]

No excuse, it was past first light *NM*

[Terry M.]

Not in the midwest *NM* *TL*