Packard Forum Index » Pre-War (1899-1942)

To me, that number stamping doesn't look factory.

It could have been a replacement motor that was stamped either by a dealer, or a DMV assigned number.

The date cast into the block will at always let you know when the block was made. A full picture of both sides of the engine can be used to interior the motor.

For example, early (1937) and later (post-war) sixes had different manifolds and other design changes.

It is not uncommon to find later sixes in earlier cars as replacement motors. This was factory authorized once earlier replacement engine stock became unavailable. Serveral service letters describing this and any needed changes to retrofit them. These replacement motors came unstamped.