Radiator issues V6 Capri Auto

Seem have an issue with the white Capri. It keeps leaking out the overflow. In saying that I drove about two weeks ago got to my destination with steam and water coming out the bonnet. Opened it up and the radiator cap was missing waited for Nrma and he found the cap in the motor ( I was looking for about half an hour and he saw it straight away) we refitted with new water and drove around the block and water kept coming out the overflow without it even being hot (waited for 1hr 45mins for them to come) the top radiator hose was really stiff and hot and bottom hose cold. So we pulled the thermostat and he reckoned it stuck closed. So we cut the end off and put just the housing back in which seemed to fix it. Now though whenever I drive it and especially like today it just comes out but my temperature gauge is not overally abnormal( it's well before halfway on the gauge). In the past two weeks after the cap came off and I don't know how that happened for starters, I have radiator flushed it twice and got a new radiator cap. Yesterday I pulled the valve covers and retourqued the heads to 80 pounds as it was meant to be a reco motor and don't think anything was done after bedding in. All this in vain and today at 38degrees in the shade she just leaks like the proverbial. Drives well feels too hot but has no proper thermostat just its housing and I'm buggered to know what it is. I was taught to bleed all air from radiator so am sure it can't be overfilled. The motor water jackets might be blocked but I doubt it. And I'm not confident that the head gasket is blown (but now I'm not confident with any of it). Any ideas or thoughts would be appreciated. Only thing to try now is pull the heads and replace the gaskets but just not sure it's the issue.

With the radiator cap off and radiator full of water, are there any bubbles?
Pressure Test the complete cooling system.  This will identify if there is a leak, then locate.
Any water in the oil?
 
Regards
John

I know I'm trying not to understand you but I'm thinking the only answer. If I pull the heads they need crack testing and machining and blah blah blah which means I lose my chosen transport over xmas. If I do it then contemplating converting it to Dport heads and manifold which I have and hoping for a C3 conversion. That's all I can do for the girl to update from its current stats unless varying from original. Understand then not original bit more driveable though.

Seems to bubble but not excessive. Rev it up and water goes down not up. Will overflow with the xtra heat after wards though.

its been that long since I had over heating probs - would a compression test show a stuffed head gasket?

Capri has 13/90 cap and two types according to Repco. Overflow and non overflow and I've tried now both types new as their cheap. And yet green fluid spews out. All I think I can do is pull the heads and manifold. Hope I find the issue or it could be lower down in the block with dreaded core plug build up issues. F me it's time for rego which I'll do first then worry about it later. But even that may be an issue which out it leaking.

h

Wiggy I'll freely admit my mechanical aptitude is way less than any aus male would  freely admit to , and I'm talking as a person who recently had to remove the thermostat housing again just to check I did not replace the thermostat upside down in the first place, but can I ask, from the above first post, did you end up replacing the thermostat after RACV did their mods?
 
I understand it probably should make bugger all difference, but it would suck if it was something simple...