I've been told head gasket or advanced timing can cause this..i'm sure it would but always????............they are 350 mags...it only happens when i just completed a 5000 rpm run........common sense sais, the exhaust is hot and its steaming when cool water hits it. I've always believed this till my buddies 30 searay w/inbds only steamed from one engine..............anyone have any input or opinions on this.... ............thanks

I don't know, but mine always steams at least a little. like you said, after WOT, the steam is increased. I don't know if this is a problem or not, but so far i haven't had any related problems.

Hot spots in the head will cause the water to "spot boil". The engine temp will be normal.... but the hot spots will cause a little steam to come out the exhaust. You don't see this on a closed presurized system because the added pressure raises the boiling point.