LIKEAROCK

I am replacing gaskets on runners and plenum but not sure, do those gaskets require a sealant, if so what kind do I use also I had someone helping but his dad just passed and I notice one bolt he removed looks different (runners to manifold bolt) it looks like the bottom part of threading is cracked but it also looks like it was ment to be that way, can anyone tell me where that one goes or do I have a busted bolt