stock headbolts are steel that thread into aluminum block. i can see why they use special thread sealer. i think it acts as a barrier for corrosion and to prevent steel/alum issues. i also think if you timesert the block you should not need new headbolts since the steel bolts are now threaded into steel inserts. yes, maybe use some type of permalock thread sealer but being forced to use new headbolts seems like an extra expense. the internet is full of stories of folks who do things contrary to the experts. anyone here reuse headbolts with timeserts and have the gaskets fail? that is the only qualified responses i want to hear. no other "i heard it so it must be true" comments.