Just wondering if gasket goo is required on the main cork sump gasket and what you'd recommend seeing as we're dealing with hot oil and not wanting it to come off and block stuff up!!

Should be permeated blue or permeated copper for heat. Check their website

I didn't think you needed gasket goo on cork gaskets.

no need i just put on a sump gasket with no sealent but if your half moon seals fall off from the rear and timing cover then i normaly put sealer on the inside.

a smear on the gasket goo usually seals any minor leaks i had on the a series i had

Oil pan gasket, cork or otherwise, needs no extra sealer.

What is does need is:
1. ensure the pan flange is flat. Many have been overtightened and won't seal correctly until straightened
2. Do not overtighten. Factory torque is really low (they are only 6mm bolts). Tighten them to spec, then go round again and retighten.

Oh, you do need sealer on the corners of the oil pan gasket

After a couple leaking on me after install and having to pull motor out again I use thin bit of Goo all round and big bits on four corners of rubbers, check rubers are right too had wrong ones once

Yes, I just checked the Datsun factory service manual and it agrees. Sealer on both sides and in the corners.

But don't use RTV (silicone) all down the sides. Use gasket sealer goo. Maybe use RTV in the corners.

I always use grey 3bond.
Also critical to a good seal is to put a dab of sealer is the very corners of the rear main cap. The haynes manual for the datsun 1200 omits this bit of info. But it's been added in for the B210 and B310 manuals.
Nothing gives me the sh1ts like an oil leak on something I've just had apart.