the bottom end has done 10,000 miles since total rebuild new wrc pistons new rings new 200 block all new .25 bearings, stripped it down toaday and turns out the stem seals are leaking could see oil weeping down the valves after it was turned over, so now what are going to be the best stem seals and head gasket to buy should i used arp nut and stud kit or stretch bolts car has been built for 380-400 bhp