I used the thick red assembly lube...only gets used between the washers and bolt head and a little on the upper threads...you need to use loctite or permatex thread sealant on the lower threads.
I realize you probemly won't listen to this but here we go. You will need to use a sealant and what ever you chose will need to be the same for all your head bolts. Why? You ask! Because the torque has to be the same for all 16 bolts. ARP makes both sealant and lube that matches or you can do what most hot rodders do and use RTV. I prefered Loctite 567 in the tube but, I got it for free. Again! I infosize! What ever you choose, has to be the same on ALL bolts. I am assuming that you have a stock block.