As Teach said, new gaskets and bolts and thats assuming if you are going that far then you are going to replace them with ARP. I did mine on the head because I didnt want to go through pulling the heads although in some cases it could be easier.

 

do you HAVE to replace the bolts when you pull the heads? if so, why is that?

 

Yes, you do need to replace them. The head bolts from the factory are TTY bolts and can't be reused.

 

In other words they stretch a bit when torqued down to the heads. Thats why guys go back in with ARP bolt that dont stretch.

 

even the intake manifold bolts are tty alot of the bolts on our engines are i found this out on my gen 2 when i replaced the retched plenum gasket and belly pan....i just assumed they were all like that so when i changed out my valve cover gaskets i replaced them too and then got told i didnt need to....damned if you do damned if you dont....i look at like this atleast its all new if you replace bolts with new ones....make sure they are quality bolts though and not just some cheap shiz......