I have a weak manifold in that over the years the clamp has rusted and deteriorated due to heat and corrosion. The manifold itself is good. I tried to get new ones..N/a at Ford, N/a at Dorman( except drivers side) , I tried several other suppliers including Carquest, no one has a contact for them. I found a set of used manifolds off of a 1995 v6 for cheap money , however the clamp was corroded. My son in law is a machinist and he got some stock the same thickness as the original, did some measuring with his guages and built a new clamp which he then ran through his milling machine and cut it into precise halves. Then he welded the two half clamps to the original clamp, making it almost doublely strong. Now I will use 7/8th stainless steel bolts, washers and spring to bolt the manifold up with the exhaust pipes. I haven't made the change yet,getting manifold bolts out is going to be tough. !