its either rings or a HG... try running the motor, from cold, with the cap off the radiator. watch for any bubbles/steam/spurts of coolant shooting out, and this will be indicative of a HG...

if you do a compression test, and get poor results in one cylinder, try adding a oil-quart-cap-full of oil, through the plug hole, and see if the compression goes up a tad, that would indicate worn rings...

and might i add SHIT!, this is what i was fearing for my motor, just havent gotten the compression gauge up here from home yet...

GL bro, hope its a HG!