OK, latest update and thanks for the replies. First, no power adders at all. The engine is NA, and 425 or so horsepower ( 370 RWHP). I figured it was a head gasket because I was driving down the road and suddenly started getting a huge cloud of white smoke from the exhaust. Pulled into a parking lot, let it cool for a bit, and checked the oil and radiator levels. Oil level was fine, no sign of water in it. Water level was down by about a quart. Put water in it, drove it like 5-7 miles to get home. As I was driving it, it still smoked, but less than before, and it smelled like a water/antifreeze leak.
I've got the intake manifold off at this point. When I pulled the intake manifold, the intake gasket on the 5-8 bank of cylinders looked bad around the # 8 cylinder. What it looks like at this point, is that the gasket let go between the rear water passage and the # 8 intake port. I say this because first, the gasket itself looks like it was distorted/broken between them. Second, there's a bit of carbon build up/discoloration around each intake port where the port meets the gasket. On # 8 cylinder, that carbon discoloration has clean streaks going down the side of the intake port, toward the valve. what it looks like, is that a leak developed there, and the water was getting sucked into the cylinder.
Tomorrow, I'll do a compression test on all 8 cylinders and see what that shows. My feeling at this point is that if I've got good compression, then the water leak was in fact across the gasket and into the port. I'll put a new intake gasket in it, button it up, and see what happens. Does this sound good? I have no objection to putting new head gaskets in it, but don't want to do it if it's not needed. Thanks in advance.
Dan
