C1 engine numbers

[Todd Petzold]

Looking for a 283 to put in my '61. Found a block that someone can stamp my VIN on. He also has correct heads, and manifold for the engine. I'm new at this, what should I look out for? Other than whether or not the block is good. Will that qualify as 'numbers matching', or am I wasting my time.

[Kent K.]

Re: C1 engine numbers

Todd,

Suggest you purchase and study both the Judging Guide for '61-'62 and the Judging Reference Manual before you commit to stamping a block for your car. If you plan to restore it and have it judged, stamping a block will probably cost you more points than not.

Regards, Kent #6201

[Terry D.]

It's only original once! *NM*

[Mike B.]

Re: C1 engine numbers

Todd,

For starters find out if the block has been bored and if so, to what degree. After about .060 to .080 of oversize, there is not much life left unless one considers expensive sleeving which does not pay for this block which is not very rare (yet).

You also need to check for casting numbers and casting dates on all of the components, especially the block and intake manifold as these can be seen by judges and casual observers alike.

The block for a 1961 should be a number 3756519 (big numbers on the rear top left), or for a very late model year build (July-end) possibly a 3789935. Post the last five digits of your serial number (VIN) and persons on this board will tell you the build date of your car.

The casting date is an alpha-numeric sequence found on the rear top left such as B241 translating to February (second letter in the alphabet = second month of the year), 24th day, 1961. Note that only engines cast in Flint, MI were used in Corvettes. One telltale sign is the single digit year in the casting code. Blocks cast in Tonawanda, NY used two digit date codes for the year. Another sign of a Flint block is a small oil galley plug in the front of the engine. Last but not least is the engine pad on the front right of the block. Restamping is the subject of great debate - search the archives for "broach marks" and you will get an education ad nauseum. Original or not, this pad is used to identify the assembly plant, day and month and how the engine is outfitted via two-letter code indicating horse power and transmission type among other things.

The intake manifolds for the car vary by HP option but assuming a base horsepower engine (single four-barrel carburetor) the correct intake manifold is casting number 3746829. Again, look for a casting date of a similar sequence to the block. This manifold is made of cast iron.

The correct heads are number 3774692 but there were several other direct substitution "Powerpack" heads with the same combustion chamber space and valve sizes. The key is to look for a peaked triangle mark on the outside end of each head. No one bothers to look under the valve covers for the casting information so you can save some money by using something other than the 692 heads which command higher prices.

Good luck in your hunt!

[Mike B.]

Re: C1 engine numbers

Check that: The date code is on the rear top right of the engine.
Mike