Auto LX and UC Toranas with ADR27A got 6cyl engines from the W sized vehicles (HQ-HZ). In Torana they had an X in front of the HX or HZ engine, hence XQL, XQD etc. So it is normal for a UC to have XZL. If it has ZL instead of XZL it is just a Dandenong plant stuff-up. The X is stamped away from the rest of the number, and is a different font as it is hand stamped, just like the 11 or 12 in front of HQ-WB Statesman engines.