there is leakage of exhaust gases from my accord 87, and it makes toomuch noise when accelerated. i noticed the exh manifold,s studs cannot be tighten as those r slipped, when i asked mechanic how to fix this problem, he told me to remove head and get it new whole from lath shop,my question is can we fix stud firmly without removing cyl head. pls keep in mind this is an alluminium cyl head. pls help me to solve this problem without removing head, thanku