Found 71 340 block

The VIN on the pan rail tells all... just because its cast in 69 doesn't mean its a 70 block.
The 1 in front of the B is the year.
The B is the assembly plant.
156652 is the last 6 of the vehicles VIN
The engine ID shows GW that means its a 71 block assembled in Windsor G =1971 W=Windsor Ont.
340 is the cu inch
P=Premium Fuel Recommended
3352 is the date it was assembled based on the 10,000 day calendar. In this case its 10-1-1970 for the 1971 model year.
0461 this engine was number 461 built that day.
A is for oversize 0.20 pistons from the factory.
Hope that helps :)