I changed the exhaust manifolds on my 64 Fury to the HP manifolds from a 69-70 B Body. The flange on these manifolds is 3/4" thick. What is the standard thickness of an exhaust pipe flange? I dont have anything to go by, and want to purchase stanless steel fasteners for when I take the car to a muffler shop to have the pipes fabricated. I am thinking the threads should be 7/16" fine thread, but need to figure out the lengths. Thanks, -- Lee Sumpter