As I stated in the title. I need to replace the nuts that bolt up to the studs on the headers. I noticed when I was putting the h pipe on that the nuts are stripped. I went to the auto parts store and the guy told me they didn't have a nut that it may be an unusual size. I went to Home Depot and bought some Metric 10 - 1.5 mm nuts and they were too tight. What size would fit and where can I find them?