sorry i thought i changed my sig. This truck is running a single S475 boost was around 60psi at WOT. figured i wouldnt have a gasket problem with this power level, best i can tell it popped the gasket on the front cylinder and flooded the water jackets with compression and split he block open. never seen a head gasket do this between the freeze plugs, water hoses, heater core and rad looking like something else would give under the pressure befor the block would but oh well all i can do now is fix it.