Thanx Jock. I have similar paste from Bosal. The problem is that after few hours it completely hardens. But I think I need something "flexible" because that gap is causing by shape change of ex man (or head) during heating.
So now are different options:
1, buy new whole maniverter (300 Eur) - but this doesnt solve problem if head is changing its shape wrongly
2, to make 100% flatness of head outputs & manivert - but again, it will still change its shape wrongly during heating
3, use double thickest gasket - this is my favourite option for now...
4, identify that gap on hot engine and use some thin piece of gasket only on concrete cylinder output (crazy solution, there could be many other leaks when its cold...)
5, buy new head - for me impossible, too expensive + a lot of work
This situation is complicated because of overheated engine...on normal engine I'll change gasket and thats it. But this is special situation