Just wanted to finish this thread off for future searchers. Problem ended up being a bad head gasket blown out of both sides of the head at the #6 cylinder. Thanks everyone.

Wow!!!
That cylinder must be running hot.
Or is it the cylinder with the loose sleeve?
The sleeve could have beaten in the crown on the gasket..

Engine Code: P0306

Land Rover Engine Code: P0306 = Cylinder 6 misfire detected Injector 6 excess emissions/catalyst damaging level of misfire.

Click to Process more Land Rover Engine Codes here