Messy Rocker Arms, what would you guys advise

[Andrij]

Hello! My rocker arms & heads look like this on both my 1970 C10 Truck (Cast Iron Heads 14014416 1980-1985 305HO, 58cc, 1.84"/1.5" valves, 7 exhaust holes) & 1974 DJ5C. What causes this & are they keepable/Salvagable? What would you guys advise?
Additional Vehicle Details:
1970 Chevrolet 1/2 Ton C10 (CE140S169178) Black Exterior with Red Interior for 600 CFM Holley Carburator Street Warrior (80457-3 1344) Electric Choke Gen 1 SBC 13 GM 391467 Date 237 3914678....302 290-290hp /327 210-350hp 2/350 295-295hp.....68....2 Bolt Cast Iron Heads 14014416 1980-1985 305HO, 58cc, 1.84"/1.5" valves, 7 exhaust holes Alternator Delco Remy 61144854