I had those like a million years ago. Good header! (car went 11.76 with them) I used the factory studs. Do not use the bolts they supply. In fact for any header the factory studs are best. I know everybody says this but I did figure this out on my own. When I installed the FRPP shorties I used their bolts. some stripped, some became loose after a while, they suck. I had to do it a second time and reinstalled the factory studs.
Also the factory gaskets should be used as well. If your worried about the factory gaskets get new factory gaskets.