According to Baugher, only one XA-26D and XA-26E were built.
Douglas XA-26D Invader
Douglas XA-26E Invader
The A-26B and C had the R-2800-27 which was combat rated at 2,000hp @ 1,500ft and 1,600hp @ 13,500ft. Normal rating was 1,600hp at 5,700ft and 1,450hp @ 13,000ft.
The R-2800-83 of the D/E was combat rated at 2,100hp @ 3,000ft and 1,700hp @ 16,000ft. Normal rating was 1,700hp at 7,300ft and 1,500hp at 17,500ft.
Engine power numbers from
Graham White, R 2800: Pratt & Whitney's Dependable Masterpiece
White has performance numbers for the A-26B, C and and B-26K.
The B-26K has an even more powerful engine, 1,900hpat 7,000ft and 1,700hp at 14,500ft normal, maximum power 2,300hp (dry), top speed improved by a few mph but at a 5,000ft higher altitude. Climb performance was substantially increased, as was ceiling and cruise speed.