I am probably an oddity here but I prefer to use a good Ariel plunger pump if I can. The one in the Red Hunter is a 1938 original which has so far given me good service for upwards of 30 years with no problems. The one in the Square dates, I think, from about 1951 but gives a constant pressure as did the one on my earlier iron Square, again without problems.
I would never run a Mk II engine on anything other than a Morgo pump though, as the Ariel original is so temperamental.
36 4G, 37 VH, 54 KH(A), 75 Healey 1000/4, 52/53 ex ISDT KHA (project).
Former Machine Registrar & Archivist, General Secretary and Single Spares Organiser (over a 25 year period).
Now Archivist once more - but not Machine Registrar.