I think we strayed a bit from topic.

Keep your H2o if it still works.
I'd go ahead and replace ICS,,,can't hardly believe you still have an original.
I've never had icing. I live at 1000 ft. el. Never iced on me up in The Sierra. Had an Opel Manta with Weber carb. In wet / frozen Ohio. Man, that thing formed an iceburge in the throat untill I invented a heated airfilter box.

dave h.
'89 Raider V6 5spd;Aisin Hubs;; Gen2 LS: frt. brakes, rear coils;U.C.arms;R.trailing arms;idler arm; rear LSD axle w.disc brakes ;2 battery system for Dog's fan; relocated ECU; custom bumpers;J.Baker receiver;Conferr roofrack; t-bar crank.