We @ Speedtech recently test fit our LS subframe headers into a stock subframe with the 6700 steering box. and they fir with TONS of room.
and the road clearance is the best I have seen. the header on the pass side is only 5/8 below the stock subframe. the drive side is about flush.
here are some pics. They are stainless and are 999.00 but they FIT.
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