Surewin Headers, Stock Mufflers

[JNC]

I've 'won' Surewin headers from Ebay for my 1999 Boxster (manual trans), which I plan to install. Outside of misaligned bolt holes issues read about here, which have been discovered on various but not all Surewin headers, are there any other fitment or other issues I should be prepared for?

I understand that the power steering fluid line should be tie-wrapped away form header to prevent fire. Plan to do that.

Anything else? Will the valves need to be readjusted? Backpressure issues? Car inspection exhaust test issues (NC)?

Plan to use existing stock muffler, O2 sensors (4) and cats. Issues?

Thanks in advance!