MAC headers for the 1998 Mustang Cobra 4.6L have 1 5/8" primaries with a 2 1/2" collector.
16 gauge steel with single port flanges to prevent loosening that may occur with
a flame cut solid flange. MAC's True Fit collectors eliminate gaskets which are prone
to leak. All MAC headers retain emissions controls and come with threaded flanges,
machined steel studs & locking flange nuts.