Possible bad head gasket

[95LT1Z28]

Ok, I just bought my 95 z28 with 106k on it. I have been keeping an eye on all the fluids. Now Ive been noticing after a short drive, the radiator will not be filled to the top (once engine is cooled) but the resivour will be at a higher level than normal. I changed the radiator cap, and took it for two 15 mi drives, and the levels of both were fine. Car ran good, but did have a slight miss before it was warmed up. Now i took it for a longer drive 25mi and the res. level is high and rad. level low, and the car missed for a little bit longer. Do I have a headgasket issue? The car is running at about 165-170. No coolant in the oil and no white or any smoke from the pipes. Car doesnt miss until about 2k-2700 before and after runs and idles perfect. What can this be?

[Fastbird]

Stuck T-Stat maybe? I would venture to say no to the head gasket issue as the car doesn't seem to be exhibiting symptoms of a head gasket being out.

[95LT1Z28]

Could the thermostat maybe be on its way out? cuz it does run cool maybe it closes to soon and doesnt let the coolant run back through? I have a new thermostat, its a 160 hypertech ill throw that in and see how it is.

[fuels94]

If your don't have heavy white smoke, or water running out the exhaust, or the overflow tank is not boiling over, but your missing fuild in the radiator. Now your starting to have a miss issue. I would check the weep hole on the water pump to see if your leaking, and if so it's leaking onto your opti.

[95LT1Z28]

The Water pump is electric, sorry should have stated that. It only misses like with slight throttle, at idle and under moderate aceeleration it is fine.

[BLK95TA]

i had a similar issue but yet i could sometimes see coolant on the ground, turned out to be a pinhole leak in the radiator.. until i let the car sit in a parking lot running and saw it pissing out the radiator on the pass side, i thought i was losing coolant elsewhere or had an air pocket.