Was the cylinder head checked for cracks or warpage? ANYTIME you have a leak of the head gasket, the heads need to be surfaced and checked for cracks, when servicing the head gasket. Also check the engine deck for true also.
When you say 'leaking' do you man the coolant level is going down, and you don't know why?
Any bubbles or white stuff in the oil? Excessive water out of the tail pipe when it's all warmed up?
If water out the exhaust when it's warmed up, head gasket or cracked head or cylinder block. Water in oil (white, bubbly) same. Neither of these, it's probably leaking somewhere else. Heater core, radiator, hoses etc.