I did that exact move, Hedman 1-7/8 headers into my ‘71 Duster. The front end linkage needs some help to clear the header, so a small dent was implemented.
Not a big deal.
On later years, the front end linkages are different so the clearance problem should be less to nil IMO.
Spark plug changes are a PIA. A tad harder than harder than this drivetrains ET up in a B or E body just due to less to no room to move your tools and hands around. I would not do this again myself. But it did work. Other than headers, the only issue (minor but a little pricey) was the mechanical fan fitment which I deleted the viscous fan for a GOOD electrical fan.
