4 cylinder opposed
4 ¾in x 9/16in Makes 4 GBU-12 Bombs P/N 1037-15
4 ¾in x ¾in Kit Makes 2 Bombs P/N 1037-2
4-1/8in X 1/4in ROCKET
4.5 inch Dia 5 Cylinder Radial P/N 1028-19
4.5 inch Dia 7 Cylinder Wasp Radial P/N 1028-5
4.5 inch Dia 9 Cylinder Wasp Radial P/N 1028-6
4in radial front 7cyl P/N 1027-13
4in X 1-1/2in Teardrop Tank
4in x 5/8in Makes 4 Bombs Type 1 or 2 P/N 1037-11