To begin with, i think i'd better say that the car hasn't been treated perfectly. But for some reason, like when sitting at the lights, the tacho stays at either 800 or 1000 and barely moves at all.
And out of nowhere, it stalls. But that doesn't happen very often. Not at every light or intersection. It just happens quite randomly and somewhat rarely. I had new plugs and leads many months ago. maybe 6 or more. Not sure what i should be looking at. Also the idle is tuned as low as it goes but it still stays at 800 or above. I just chuck the air con on to fix it, but it doesn't always work.

High but lean idle indicates an air leak somewhere after the MAF sensor.

...could it possibly be at the intake manifold?

After changing the head gasket, i reused the old intake gasket rather than wait for the shops to open

Idle speed control been replaced? Cleaned? That could be your problem, or if it's not able to be adjusted and sits at 800 no matter what, could be an issue relating to somewhere around the throttle body

...could it possibly be at the intake manifold?

After changing the head gasket, i reused the old intake gasket rather than wait for the shops to open

Did you torque the intake manifold bolts and nuts in the right order and to the right torque? Strip any bolts?

The steel gasket is ok to reuse.

oh. My intake gasket was a cardboard/paper sort of material. It was not in one piece, but was not in terrible condition.

Bolts were tightened properly on the head, but im not so sure about the intake. It just so hard to get to

edit: I guess i'm lucky its running so well in that condition.
could have something to do with idle speed control. ive never cleaned it, or even taken it off.

Thanks for the advice, sounds right on the money. Better than i'd get from a mechanic, to say the least. I have a real problem with mechanics, thinking they are all out to screw people over and charge them more than they really should.