I got the engine on the stand to start tearing down. The main seal has been leaking for a while apparently, as well as the oil cooler. This thing is nasty!! The heat riser on the right side has a hole rusted through it and "patched" with a beer can and hose clamps. I sprayed PB Blaster on everything a few days ago when I got the engine out and again yesterday. I start taking the exhaust off and the #1 comes loose with ease. I go to #3 and start stripping the nut. I grab a 1/2" (12.7 mm vs. 13mm) and still strip it more. I give it a couple small whacks with the ball-peen and another squirt of PB Blaster (I'm out of Kroil) and move to #4. I get the top one of #4 loose but then it stops. I strip the bottom one out. I get the top one on #2 loose but can't get the bottom one to move. I go back to #3 with vise-grips and of course, I snap the stud. I break out the torch and try #4 again to no avail. I decide to let them soak overnight and try the intake. All four nuts come right off at the head and the right side heat-riser comes right out, but I immediately snap both bolts on the left side heat-riser. The pisser is that I don't have any studs. I had them in my hand at BugJam but didn't buy them for some reason. This engine is box-stock with all the exhaust and heater stuff still on it. It's a mess.