Did some digging and here are some things you should look for. As mentioned above, it should be a Lansing built car. The Vin will read as follows, a 'X' will appear as the 5th digit in the vin if it is a W-30 car, a 'U' is the other 455, a 'M' will appear as the 7th digit for a Lansing built car.
Heads= Look for a 'Ga' on the left side of the head.
Exhaust manifolds= Look for 'W' on the drivers, 'Z' on the passenger side
Intake= On a W-30 car it will be an aluminium piece (not painted) with 'Olds W-455' on the intake runner , casting # 407570, and look for a letter 'A' in the valley by the water neck. No EGR on this. If it is a 'U' code engine, it will be an iron manifold.
As for the engine pad, it is under the drivers side head. According to 442.com, it is very unlikely that the pad will have the correct vin stamped in.
Hope this helps.