I am not familiar wirh the way the Morgan breathing set up is/was, but the x/flow in the basic Ford simply relied on the Filler Cap on the Rocker Cover to do the job. Cheap copy Airfilters didnt help either.
A good quality Airfilter or exchange the Airpan into an Aftermarket race one and regularly flush out the Filler Cap which had a Gauze Trap inside.
