i think it is a standard T55 12,7 mm cupolar
for the T55 M1970.
Syrian army uses 14,5mm for AA on some T55.
MIG makes at 14,5 mm turret gun convertion for
the Tamiya T55 kit (and a North-Korean laser).
You can use the Tamiya T55 cupolar for this truck/
AA gun convertion in 1:35 scale.
Or you can use the MENG light truck 14,5mm
LINK to MIG Convertion