b2600 head question
 

i have an 88 b2600 4wd. I was driving down the road the other day and i either popped the head gasket or cracked the head. If you keep the motor revved up it runs fine but if you let it idle its filling one of the cylinders with water. My question is are the heads bad to crack on these motors? my buddy had a 2600 that the head did crack on but i wasnt sure if it was a common problem with them or not. Hopefully i can get lucky and slap a gasket on it and sell it, but with my luck probably not... thanks for any help in advance.