When you specify UTILLOC=WORK, and the WORK data set is allocated with DSNTYPE=LARGE, the UTILLOC allocation does not inherit the LARGE data set type as expected.

Here is an example:

//WORK DD UNIT=3390,
//                     SPACE=(CYL,(3000,3000),RLSE),
//                     DSNTYPE=LARGE

The UTILLOC allocation should mirror the above allocation. However, the system assigns the following default:

ALLOC UNIT(3390) SPACE(274,274) CYL DSNTYPE(LARGE) NEW DELETE

This value corresponds to the maximum number of tracks that can be allocated on a single volume for a DSNTYPE=BASIC data set.