Hi All,
a real dumb question(newbie), wanted to verifiey matching #'s
where do I find them on an 81 ??

 

Matching numbers means many different things to people. Some just refer to the engine, while others include the tranny, and other parts such as the alternator, manifolds, carb, etc,. Your best bet is probably to pick up a book on restorations at one of the major book store chains that covers your year.

 

Not a dumb question at all and as suggested, an NCRS Technical Reference guide the for 80-82 (NCRS.org) is your best source. And there are different degrees of "matching Numbers." For your purpose, let's start with basic.

Basic matching numbers means that the engine suffix pad, VIN tag and transmission VIN derivative match up. The engine pad will have what's called a VIN derivative stamped on it. The pad is at the front end of the engine (passenger side) under the AIR pump and A/C compressor. The VIN derivative is a part of the VIN and includes the "build sequence number" or last eight characters of the VIN and is identical to the last eight characters on the VIN tag (windshield) if its "matching numbers." Usually you need a flashlight and mirror or scope for best viewing.

For example, my 78 VIN tag reads 1ZL878S409041 while the VIN derivative on the engine pad is 18S409041.

the VIN tag is located on the driver's side windshield post.

Finally, this same VIN derivative is stamped on your transmission and location varies depending on the transmission installed on your Corvette. This is hard to locate unless you know what your looking for (reference guide) and its on a lift.

This should get you started.

PS...the VIN derivative is also stamped on the frame on rear driver's side where wheel well kicks up...but you nearly have to pull the body to view or get a mirror and flashlight.