Perhaps as a competitor to the Grumman Design 55 (XTB2F-1) for the cancelled Avenger follow-on?
Grumman Design 55(XTB2F-1)
Span: 74'
Length: 52'
Max speed: 338mph
Ceiling: 31,600'
Range: 3,060 miles
Two 2,000hp R-2800-22
Two power turrets each with twin .50MG
Two fixed .50MG and 75mm cannon in nose
Two .50MG in each wing
Single torpedo or up to 36 100lb bombs in ventral weapons bay.
'Grumman Aircraft since 1929', Rene Francillon, Putnam/NIP