Closest i could find is....
HZ series 1977-1980
3300 engine, 3.298lt, 1977-1980, 82 kilowatts, XQL,ZL
4.2L engine, 4.142lt, 1977-1980, 120 kilowatts, QR,ZR
5.0L engine, 5.044lt, 1977-1980, 161 kilowatts, QT,ZT
It will have 253 or 308 cast into the block on the passenger side - the side with the starter motor. But the ZR says it is as stated above.
As Abba fan said, look on the side of the block...
I have never heard of a ZZ prefix. As others have said, check the casting on the side of the block. Maybe ask the owner to do this for you???
Reaper
This may help
MonaroParts
QldKev
I have a 1 tonner here that has a 253 in it and the engine number starts with QR if that helps
Is that an HQ 1 tonner? As i was always thought QT was an HQ model 308 and QR was an HQ model 253....But the 2nd post in this thread says HZ. Wierd.
Only way to really know is the casting on the side of the block, many an engine number would have been changed over the years....