Fender and hood rubber

[Westislander]

How important are the rubber seals between the fenders and body and at the hood hinges? I am reassembling my truck and am debating if I need to install them

 

[DanMcG]

I know the long ones at the end of the fender that run parallel to the doors front edge had some of the worst rust on the whole truck. I'm considering leaving them out

 

[R Carnella]

They are probably only there to quite wind noise.