* The cowl tag: This is a metal plate usually located on the driver's side, under the dashboard, near the firewall. It will have a body number, and possibly an engine number. This is the most important identifying tag.
* Engine block: The engine block itself would have a casting number, which is not a VIN but would help identify the engine.
* Frame: Some manufacturers stamped numbers on the frame, but this was less consistent than the cowl tag.
It's important to note that these aren't VINs in the modern sense, but are the closest equivalent for a 1946 Chevrolet. You'll need to research what the various numbers on these parts mean to fully identify your specific vehicle. Chevrolet enthusiast clubs and online forums dedicated to classic Chevrolets are excellent resources for decoding these numbers.