The 235 is also a larger, heavier engine than the 292. The 235 is a "wide" six, whereas the 292 is narrow. They both are about the same height.

Easiest way to tell is look at the pushrod/lifter cover side of the block. If it has a single large pushrod cover then it's definitely NOT a 292. If it has 2 pushrod covers about 6 inches in height then the engine is DEFINITELY a 292.

-ftyler