85 E 350 Dip stick issue (missing) 6.9 L
 

I have scoured the world for a dip stick to no avail. The tube is fine and in place. Engine was rebuilt and the dip stick was lost. This was before I got this van. So I have decided I have to make one. Does any one know what the length is or should be? Or does any one have one I can buy? thanks