Bondo - I have no history unfortunately. I just bought it 3 weeks ago. I've only run it on muffs in the driveway. Noticed the misfire almost immediately, shut it down, pulled the plug, found it wet. Replaced the cap, rotor, wires,plugs... no change. Was setting up for a compression test when I saw the geyser for #4. Local marina said the 2 large water jackets at the back of the head freeze and push through the head gasket if not winterized properly (canadian winter). I just don't know if I show start looking for an engine, or tear this one down and see I find a smoking gun...
Forgive my ignorance, but what makes you suspect a cracked block vs. a head gasket?
Thanks