A quick look about will settle the issue as casting and part numbers abound.
- The 292 will measure close to 10.9 inches from pan rail to head deck, where the low deck blocks will be about 9-1/8 inch.
- On the passenger side the side covers of a 292 are 6 inches tall, those of the low deck engines are 4 inches tall.
- With an exception for some early Novas low deck blocks, the tall deck 292 will have the right (passenger) side fuel pump in the middle of the block and the engine mount positioned forward of the pump. The low decks will have the fuel pump forward and the engine mount in the middle, this is where some early Nova low decks used the 292 positions.
There ya go a quick and dirty way to tell a low from tall block GM I-6.