[Joe's Garage]

Does the block have a partial VIN down next to the timing cover?

That will be what signifies which vehicle it was installed in originally.

The number above the 'WA' is the Engine Unit Number (EUN) and is kind of a serial number that Pontiac used to keep track of engines.

Unfortunately, there are no records of which vehicle the engine went into based on that EUN for the 1970 model year.

Good luck with the search!