I have Felpro gaskets (not sure the number) and I re-used the stock head bolts. The GT40 heads were milled .010 and magnafluxed crack free when installed. Thoroughly chased the block thread holes with tap and wire wheeled the bolt threads and followed all other required sealing and lubing of threads when installing. Tq to stock specs. Been running this combo for over a year prior to the V3 install with no issues. (not to suggest the V3 is related to the problem)
On mine, the temp gauge started fluctuating higher and lower but never overheated. When I checked the coolant level it was about a gallon low. Then, I found coolant drips hanging off the bottom of the gas tank cover so obviously it puked. After filling the coolant and letting it warm up to operating temp while idling everything seemed fine. Then I took it for a test drive and put the hammer down a few times. It puked again. Judging by the area of the mess, the coolant must be rapidly expanding under heavy load and blowing out of the overflow.
I filled it back up and checked for any major leaks again but found non externally. Got out the IR thermometer and while running at operating temp idling checked the temp at the intake just before the T-stat, and at the radiator directly next to the upper hose connection. At the T-stat housing 185 degrees, at the upper hose to rad connection 125 degrees. I'm hoping this indicates the coolant from the engine is not circulating into the rad (bad T-stat). I mean, how could the temp difference between those two places be 60 degrees if the coolant is flowing like it should be? There's no way the coolant temp drops 60 degrees just by flowing through the upper hose. Anyway, while testing at idle I'm assuming the heater bypass was moving just enough coolant through heater core to not let it over heat at idle but that surely wont stand up under heavy loads so thats why its puking when pushed harder.
In considering the possibility of a head gasket blown, I have a question. If everything else is good, coolant is the correct level, engine running great with no missing or any other recognizable conditions, how does the bad head gasket cause a sudden expansion of the coolant enough to make it puke? I understand over time a bad head gasket can consume the coolant through combustion and once the level gets low the engine overheats resulting in expansion. But, with full coolant and everything else good, I'm struggling to realize how a head gasket leak would cause a sudden expansion. If I'm unaware of or missing something, please school me.
