I have a slightly cracked header flange where it meets my down pipe. I wouldn't pull my head and replace it unless I was swapping in an upgrade for the 0331 time bomb.
That being said, I will continue to goop muffler cement until I can gather parts to do that exactly - pull the head, install new manifold on new head, put back in as one unit.
'00 XJ Sport, White - almost done for now...
'11 Town and Country - people mover :-(
'88 XJ Up Country, '01 XJ Sport, '08 KK Limited, '98 XJ Parts Donor, '07 XK Limited (the Stall-ander)