PDSEs use a physical block size of 4 KB, the same size as an MVS page. These 4 KB physical blocks are also often referred to as pages.

The DCB block size does not affect the physical block size and all members of a PDSE are assumed to be reblockable. If you code your DCB with BLKSIZE=6160, the data set is physically reblocked into 4 KB pages, but your program still sees 6160-byte logical blocks.