Well, I bought a set of ARP head bolts from Summit that just came in today. I ordered the ones that their site said were for my car, and I got the "high performance" (basic ones, part number 123-3601) not the "pro series" (studs) or stainless. When I looked at the box today though, the description on their sticker says "Buick Stage 1 head bolt kit". Before I open to box to look at them, I wanted to make sure I got the right ones. I don't really know the difference between the stock and stage 1 heads, are they the same as far as bolt number and sizes go, or did I end up getting the wrong set. Please help me out, and if I did order the wrong set, does anyone know what the correct ARP part number is so that I can get the correct ones? Thanks!