Oil Pump Cover 178-6538 for Caterpillar CAT 3066 C6.4 Mitsubishi S6K EngineOil Pump Cover 178 6538 for Caterpillar CAT 3066 C6. 4 Mitsubishi S6K Engine Part Number: CA1786538, 178 6538, 1786538 Engine: Caterpillar: 3066, 3064, C4. 2, C6, C6. 4 Mitsubishi: S6K Applications: Caterpillar Excavator: 311C, 311D LRR, 312C, 312C L, 312D, 312D L, 313D, 314C, 314D CR, 314D LCR, 315D L, 318C, 318D L, 319C, 319D, 319D L, 319D LN, 320C, 320C FM, 320C L, 320D, 320D FM, 320D FM RR, 320D GC, 320D L, 320D LN, 320D LRR, 320D RR, 321C, 321D