What exactly is the story with this engine? Did you blow a head gasket, and changed heads at the same time? Thats obviously not the head that was on it, coz you said it didn't have a hole.

We run it without the cover on, and not a drop of oil was to be seen. Is it the A-series push-rods that have the hole for the oil to travel up? cant remember.

Pretty sure oil travels up past the T-bolt, coz it's skinnier, and up into the rocker assembly....

Or straight from the block up into the head via that little hole your gonna drill....

been a while since i worked on A-series. Have you got the head off? I can pop round have a look if you like...on the weekend

the third cylinder wasnt doing anything so i had another engine there and decided to change the head. then realised i had put later model head on it. but i have drilled hole and oil is comming through so car is running all good.

Again, 'WHAT' head gasket did you use. Yes I know that you got it from Repco, but what was the application that was marked on the packet?

Did it say Datsun A10, or Datsun 1000 & 1200?
If you are using a front distributor engine that is essentially stock, then that is what you need to see on the gasket package.