actually....... here is the short story on mine.
i choped those neck downs off, and used a short piece with those sealing band type clamps, and i had a problem with it wanting to sit on the frame. i would move it anf tighten everything down, and a day later it would be sitting on the frame again.
took it to a muffler shop to see if they could do better. they yanked out my short piece and the other two pieces the i had cut the neckdown off of. they replaced my three pieces with one long straight 3" piece of stainless, and clamped it in place. after they did this everything lined up perfectly, and they didnt have to adjust the dp at all.
so basically...... i think in order to keep the DP off the frame you need the support of a somewhat rigid exhaust. its still really tight, but its not touching. i have about 1/8" clearance.
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