i had 220k+ miles on my once cam until i finally got rid of it. blew a head gasket or head was worped. every couple days i had to retighten the head down. but through all the shit that its tried to do hurting itself, it never blew up on me. The water pump exploded and my mech fan blew to bits and put a huge mosquito bump on my hood. I think its all single cams that like to be badasses.