i just picked up my new project a 91 gt and its completely stock. I dont know much about 5.0s as ive had the 4.6s. My buddy gave me a set of crane 1.7 rr and i tried installing them last night and the bolt was just a little to big for my stock head. Could i go to the hardware store and get some grade 8 bolts that are the rite size? Or is there something special about the bolts that came with them? Any help is greatly appriciated!