Y'all have me paranoid about HG issues. I don't know if the one on my 80 has ever been replaced before, but I do know that all of the coolant hoses (including PHH) was done. I'm very religious about maintenance (as seems to be the case on this site). I completely check the cruiser over bi-weekly. So if ANYTHING is out of place, I'll know it. Well, I noticed that my coolant level was a tad low (like 1" below the line where it usually resides) over the course of about 1500 miles. My mind immediately jumped to the HG... Thanks guys. Backgroud: Extremely well maintained, doesn't leak a drop of anything, BUT it does appear to be a little wet on the very bottom of the radiator. BTW, it's a new radiator with around 5k on it. So, that would probably explain where the bit of coolant leaked out, and why it no longer sits at the FULL mark. Case closed right? Well, for some reason I still couldn't sleep well, dreaming about HG issues. So I do tons of research on here, and read about this "Bubble test" that you can perform. Keep in mind that I'm very mechanically inclined, have built many motors from the ground up, and have encountered headgasket issues on other vehicles in the past. So I'm well aware of what burning coolant smells like, and what normal coolant should smell like. While the cruiser is fully warmed up, I have my wife hop in and gently bring the revs up to the 3,000rpm mark, while I watch down inside the coolant reservoir. That's when my gut churned. After holding at the 3k mark for a few seconds I saw a couple bubbles, then a couple more. After that, it was about 1-2 bubbles every second. Since then, I've performed every test I know to do on the cruiser, so I'll break down what's been done, and what I know so far: - Purchased/Used block sniffer 4 separate times on 2 separate days. Perfectly clean results. And just so that I would know what "yellow" looked like, I held the sniffer in front of the tail pipe once... - No cooling issues - Runs absolutely perfect - No fuel smell in the radiator or the reservoir - Oil is extremely clean (doesn't burn any between 3k changes) - No "milky sludge" under the oil cap, or at the top of the dipstick tube - No smoke/coolant smells out the exhaust - Coolant is very clean and clear All of that tells me that the headgasket is probably fine. However, there are still bubbles in the reservoir when held at 3,000 rpm. My question is (and a long way to go about it): Are some bubbles in the reservoir normal? I was unable to find a definite answer on that. Also, my radiator cap IS original. Think that might have something to do with seeing bubbles? Any light you can shed on the subject is greatly appreciated.