when fitting gx head to a14 are there any mods to be done. i was told that the oil channel had to be changed for oil to head

If it is a true Datsun 1200 GX head (1970-1973), it will have the oil passage drilled in the head face that all original A-series heads have. If it is a 1973-1975 A12T head it will be identical but without the oil passage.

In other words, no different than swapping any early head to late block.




You will need an intake manifold for the GX head or A12T head, as the ports (30 mm x 36 mm) are much bigger than A14 ports (28 mm x 34 mm).