1999 GMC Suburban steam coming from tailpipe

We recently changed the intake manifold gaskets because the vehicle was loosing coolant. After changing the gaskets, there was another leak (rear heater hose valve was busted). When we started the vehicle up, steam started coming from tailpipe, the vehicle has always ran strong and with no noises except for a lifter tick. My husband thinks is it is the head gasket but does not want to change it without changing the crankshaft. Is this necessary to change when changing the head gasket, if it is the head gasket.