I have replaced the dowty washers on the pipe connected to the rear of the power steering pump but carnt get them to seal. Are these the correct washers to fit or shoud they be copper washers.

I also want to fit a snorkle and hope to fit one for the 200tdi engine as I intend to replace the NA engine for this engine in the future. Will this snorkle fit and will I have to modify the air box. Can I also just cut a hole in the nearside wing or will I need to replace it