JCL : Concatenation of datasets with different blocksizes

Concatenated data sets can have different block sizes. In a few cases, the data set with the largest block size must appear first in the concatenation. (Note that you can state a value equal to the largest block size for BLKSIZE on the first DD statement, regardless of what the actual block size of this data set is.) Certain data sets can be concatenated in any order of block size; these are:

Partitioned data sets (PDSs), and partitioned data sets extended (PDSEs) without member names coded on the DD statements.

Sequential data sets that are DASD-resident, tape-resident, or in-stream, and are accessed by QSAM and use system-created buffers.

Sequential data sets that are DASD-resident or in-stream, and are accessed by BSAM.

I ran a test with SORT Concatenating a tape dataset and a DASD dataset with the blocksizes 27888 & 32702 without any problem