e250 4.9l exhaust leak

[99redtj]

have 96 e250 van, replaced exhaust mantel folds but there still is a leak around the mantelfold area.can't tell where it is leaking at.

Is there something i should know about this 4.9l (300 straight six).or did i do something wrong.

 

[junkyard jim]

Head warpage can do that, but aftermarket gaskets are your best friend to seal it up (make sure it's not the EGR port or O2 sensor port that's open)