Australian Car Repair Issues? Ask an Auto Mechanic for Answers ASAP
I built a few Datsun A series engines.
This write up will help you.
If the head is within spec for flatness, it is a personal preference whether you have it machined or not. Also depends on headgasket material.
If you have the bolts with 13 on them, you can reuse, otherwise update to 13s.
Do you need any further help?
Have you got a head gasket set with the head bolt torque sequence?
I hope my advice has been of assistance to you.