I OWN A 1978 TWO TONE VETTE. I NEED TO KNOW WHERE TO LOOK FOR THE NUMBERS STAMPED ON THE ENGINE. I'LL NEED TO FIND THE CASTING NUMBER, VIN NUMBER, AND ANY OTHERS I NEED TO DETERMINE ORIGINALITY OF THIS CAR.

Hey JOEM,

The casting number for the block is on the back of the block on the top,left hand side of the flange that the transmission bell housing bolts to. You should be able to look straight down behind the distributor to see it. You may have to remove the wiper motor for better visibility. The casting date is on the right side top, rear flange.

The engine assembly code and VIN is on a pad on the front right side of the engine block just below the head. This will tell you what month and day the engine was assembled, where it was assembled and what the intended application for the engine was. Hopefully the VIN matches that on your left side windshield pillar.

The casting numbers and date for the heads are on the top side of the heads. You will have to remove the valve covers to see them.

Good luck and I hope you have a match.

TO THE RIGHT OF THE DITRIBUTOR I FOUND T 20 CONV. TO THE LEFT OF THE DISTRIBUTOR I FOUND E2870, 3970014, CM AND A CLOCK IN DOTS WITH AN ARROW POINTING TO ONE O CLOCK. I DID NOT FIND THE VIN NUMBER YET ON THE ENGINE BLOCK. ALSO FOUND SOME NUMBERING IN THE RIGHT FRONT WHEEL WELL, -H FOLLOWED BY THREE OR FOUR SERIES OF NUMBERS. IS THERE AN INTERNET SITE THAT COULD DECIPHER THESE NUMBERS? THANKS FOR ANY HELP.

Hey JOEM,

I did some research in my reference books and came up with this: The engine in your '78 appears to be a 1970 model 350 Cu.In.engine. It looks like it was cast on May 28, 1970 and based on the fact that it has 2 digits for the year designation ( 70 ) instead of the typical 1 digit (0), the block was cast at Chevrolet's Tonowanda plant. Most small blocks are cast at the Flint plant. Any way the 3970014 casting # confirms this as these blocks were only cast from '70-'72. My references state that it is possible that some late '72 and early '73 Corvettes were produced with this engine, but the engine in your car( cast in 1970) probably came out of a Camaro and had a rating of 300 HP. According to the Corvette Black Book, the correct block casting number for your car should be 3970010.

If you can find the assembly code that is stamped on the pad on the front of the block underneath the right head, that should confirm what I have said here. You may have to remove the A/C compressor to see these numbers. They will be stamped into the pad instead of raised features like the casting numbers. If the pad is blank, that means that more than likely the engine has been rebuilt and the deck was milled. If that is the case, you only have the casting numbers and dates to go by. Let me know what you find. I have a reference for assembly codes as well.

I cannot guarantee that this information is 100% accurate, but I have cross referenced several different sources and they all lead me to the same conclusion, so I am confident in my theories. Hope this helps.

Jon

THANKS VERY MUCH FOR THE INPUT. I'LL TRY TO FIND THE REMAINING NUMBERS THIS WEEKEND.ONE QUESTION. IF THE ENGINE TURNS OUT TO BE WHAT YOU SAY, DOES IT IN ANY WAY DEVALUE OR DETRACT FROM ITS INTRINSIC VALUE AS ORIGINAL?

Absolutely, but not to an overwhelming degree. While the 78 SA cars are not the high dollar cars on the market such as the 67 L-88's or the straight axle fuelie cars, they are a collectible anniversary edition and their values are increasing as they get older. If a potential buyer is looking for an all original 78 anniversary edition, the fact that the motor is not original will hurt the value of the car. On the other hand, if a potential buyer just likes the looks of the 78 SA cars and wants a good example to drive and enjoy, the non-original motor may make no difference whatsoever to him. It just depends on what the buyer wants. If you like the car and plan on keeping it, just take care of it and enjoy it. If you plan on selling the car and want to make it as original as possible, you can try to track down the original motor. The next best thing would be to find another motor out of another 78 that was close to the production date of yours. It will never be the original motor, but it will be as close as you can get without restamping or forging a block.

Let me know what you find with the numbers.

Jon

One other question: What color is your engine? Pre-77 engines were Orange. 77-82 engines were light Blue.

Jon

THE ENGINE COLOR IS BLUE. I FOUND A CODE 014 ON THE RIGHT FRONT OF THE ENGINE BLOCK. ON THE PAD UNDER THE VALVE COVER,PASSENGER SIDE, I FOUND T0620 CNV. THERE IS A VIN NUMBER BELOW THAT BUT I'M HAVING TROUBLE DEFINING IT.THAT WHOLE AREA WAS COVERED WITH A RED-TO-PINK PAINT THAT I HAD TO SCRAPE OFF. IT SEMS A LITTLE "FISHY" TO ME THAT THE AREA MAY HAVE BEEN ALTERED. I'LL HAVE TO GET THE CAR IN SOME BRIGHT SUN WITH A MAGNIFIER TO SEE THE VIN.

Hey JOEM,

The assembly code (T0620CNV)that you got off of the front pad confirms the casting date and the origin of the motor. The "T" designates that the engine was assembled at the Tonowanda plant in NY. The 0620 is the date that the motor was assembled (June 20th)which falls right in line with the casting date for the block (May 28th). The assembly dates typically fall within a couple of weeks of the casting date for the block. The "CNV" suffix designates the application for the engine. All of my sources agree that this engine started life as a 250 HP, 350 cu in engine with a 2 barrel carburetor. It was originally mated to a TH350 automatic transmission and was installed into a passenger car, either a Caprice or Impala.

If the VIN number matches that on your car, then one of them has been altered. If it does not, then I would bet that the engine pad has not been tampered with. The Red or Pink paint may have been applied so that the numbers could not be easily read and compared to the cars VIN.

My guess is that the VIN number that you find on the block will not match your car's and probable belongs to a long gone 1970 Impala or Caprice.

This motor was originally Orange. It has been repainted Blue.

Hope this helps.

Let me know what you find or if you need any other information.

Jon

SO WHAT YOU'RE SAYING IS THAT IT LOOKS LIKE A PREVIOUS OWNER SWITCHED ENGINES FOR MORE HORSEPOWER? OR DID THE GM ASSEMBLY PLANT USE AN OLDER CRATED ENGINE? IF MY CAR WAS PASSED OFF AS 185 H.P. (IT DOES HAVE ONLY ONE AIR INTAKE ON THE DRIVER SIDE) IS IT ACTUALLY A 250 H.P. ENGINE? DO YOU KNOW OF AN INTERNET SITE THAT TRACKS THE VIN HISTORY BEFORE 1980? NOW THAT IT LOOKS LIKE I HAVE A NON-MATCHING NUMBERS I'D REALLY LIKE TO TRACE THE HISTORY OF THE CAR.