How many feet in a block are there?

It depends

It is important to know that there is no standard size of a block. The main idea is that blocks vary in size depending on which city we consider.  For example, the standard block in Manhattan is about 264 feet by 900 feet.  There are also American cities with 600 feet blocks or with 200 feet blocks.  In Melbourne, Australia, blocks have 656 feet.  In New York, some blocks are about 328 feet.  The main idea is that there are no standard blocks.