i recently put my 4to1 header on and noticed that i have an exhaust leak. i used the stock bolts with the springs and closed nuts on the end. i belive the leak is coming form the header to the exhaust cause i used the springs. can i get some feedback. i was going to try out just some bolts with washers and nuts to get a tighter surface. the new header is not threaded so i think its leakingfrom there cause its noticable.