A 351 Cleveland is NOT a "Big-Block"
The 351C is a small-block engine! The rear face of the block and the motor mount locations are the same as the 289/302/351W. What makes the Cleveland "bigger" is it's BOSS 302 style cylinder heads - they are much wider than Windsor style heads. The 351C deck height is 9.2", so it is a shorter block thna a 351W, but, due to the size of the cylinder heads, it's overall width is greater than a 351W.
The engine in the pictures is obviously not a Cleveland, as it has 6-bolt, 289/302/351W style valve covers. The 351C has 8-bolt valve covers, like a BOSS 302 (and 351M/400M). Also, a 351C block has the theromstat location in the block (which the engine in the pictures does NOT) rather than in the intake (like a 289/302/351W).
regards,
cobrajeff