Hi Paul
They make up the rain gutter on the rear frame.
They are welded down the inside of the frame with the bigger end at the bottom
There should be two other pieces, not the same as them, that make up the top and bottom of the channel.
Once all welded in you then need to make up some corners, most people use a bit of tubing . You can then fit your Engine cover rubber on this to make a seal
You can see the rubber hanging over the piece you have asked about
Mick
