I've been slowly getting my 92 All-Trac going, and it has a serious coolant problem. Overheats, and dumps antifreeze from the overflow. Fans work, everything seems OK. Per suggestions from others left the radiator cap off, and under acceleration coolant flows out of radiator like a fountain. This means the exhaust pressure is getting into the cooling system, usually caused by a bad head gasket. But doing more research, it seems this may be a cracked block. I'm already intimidated by a head gasket replacement, but don't want to do that only to find out it is a cracked block. Any way to diagnose this before hand?