You cannot override management class attributes via JCL parameters. With SMS, MGMTCLAS overrides the attributes defined in the DATACLAS parameter for the data set. See Overrides.

The management class for a data set defines a maximum value for the expiration date or retention period of the data set. This maximum limits the values that are specified on the EXPDT or RETPD parameter, or defined in the data class for the data set.

An ACS routine can override the management class that you specify on the MGMTCLAS parameter.