[Ccass]

here are pictures of a standard manifold downpipe installation. Notice how the flare is not even close to the studs. There should be no need to grind the pipe down on these downpipes. This manifold is fully seated and should not leak.



here are pictures of a HO/RA manifold downpipe installation. Notice how the flare is actually touching the studs. This can prevent the flare from seating properly if it can't expand upon tightening. The Left hand picture shows the grinded flare. There is a larger gap above the flare and on the sides. This manifold is fully seated and will not leak.