Thanks simmie! I knew I wasn't hallucinating ... I just can't file for toffee
The confusion probably sprang from these being considered Avro projects while having Hawker Siddeley Type numbers
The Airbus A300B-based proposals were:
Type 820: 1970 Hercules replacement proposal. High-winged, ramped configuration. Rearranged Airbus A300B wings and tail components. Span 147 ft, AUW 264,100 lb. 2 x RB211-22. Not built.
Type 826: 1972 enlarged variation on Type 820. A300B-2 components. 2 x CF6-50, RB211-22X, or RB211-524. Span 147 ft, Length 151 ft 7 in, Height 49 ft, AUW 290,000 lb. Not built.
The Type 841 was among those that led to the A400M (and sounds very similar to the four-turbofan concept Greg posted).
Type 841: 1983 design for Future International Military Airlifter (FIMA) contest. T-tail, 4 x turbofans.