This listing is for one set 1979 351M/ 400 Ford Truck exhaust manifolds and collectors.  They are in good used condition and have minimum corrosion damage that these are prone too.   Inspection of these did reveal a slight hairline crack  in the middle of the passenger side manifold that is about 2" to 3" long.   See pics.   It's hard to tell from the photo but I did look down the runner and it appears that it is on the inside also.     It might or might not be an issue.  It is just something I noticed.  All of  the mounting tabs are good and intact and there are no broken bolts in the down pipe flanges.    These are clean western parts, Clean them up or install as they are.  Questions gladly answered.  These are heavy as they weight 42 lbs.