Head cracked???

[MA70-3.0GT]

OK so the symptoms I'm getting are pressure in the cooling system after literally cranking the car for 5/10 seconds without firing up. (which only happened because the iffy accordion hose came off the turbo again) Not enough pressure to make the hoses hard, but pressure nonetheless & I'm thinking if a HG was leaking that badly there'd have to be coolant burning (not happening), and also after the engine'd run for a few minutes it would end up blowing a hose off or forcing all the water out of the cap.

This is not happening & in fact once the car's started and begins to warm up the leak appears to get less and less until once up to temp & burped, you'd swear there was nothing wrong. This is making me wonder if there could be a crack in the head which is opening up when cold allowing the compression loss into the coolant & closing as the head expands thus reducing the symptoms.

I'm pretty sure it's not just an airlock as I've burped it a couple of times & had the heater working nicely, plus how would the cooling system get pressurised without any heat if it were an airlock? That & there's the bubbling sound from the heater on startup sometimes...

Now, bearing in mind that the car has had a complete refurb. on the head could it be that the gasket was simply installed badly & is causing this (why would a blown gasket get better with heat?) or could the head have cracked?

Either way I'll be stripping her down & finding out for sure but I was just wondering how prone to cracking between a combustion chamber & water jacket the heads are & if it's really worth me having the thing crack tested or just re-skimmed, fit a new gasket & hope for the best?

Cheers, Dan.