I know nothing of this motor, but on most motors those symptoms are likely to mean at least a blown head gasket.
Next is a blown head gasket and cracked/warped heads.
Finally, both of those and some sort of bottom end problem.
I'd be pulling the heads myself and taking a look, it will be a lot cheaper to repair if it's only head gaskets, you could take the heads to get tested, then go from there.
Of course i do all my own work, so labour may get you on the repair vs replacement scenario.
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