Go with a single flange style, like the Ford Motorsport or even the Flowtech. I have heard MAC's warp and don't fit well at all. 1-5/8 is the way to go. I have the Flowtech's on mine, and just picked up a set of FMS 1-5/8 unequal length shorties at a swap meet for $200, ceramic coated and brand new in the box.
Get the Stage 8 locking header bolts too. Once they are on, you don't have to re-tighten them.
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