Is this a 277" or 303" 1956 engine? See pictures

[Ken Bartz]

Jerry,
I have, below, the specs from the "Standard catalog of Chrysler".? There, it says what carburetor you should find on these specific engines. (who is to know what has been changed).? Also given is the stroke, if you should be inclined to stick something down the spark plug hole.? BE CARFUL NOT TO LOOSE IT.

(V-8) Overhead valve. Cast iron block. Displacement: 268.8 cid. Bore and stroke: 3.63 x 3.256 inches. Compression ratio: 8.0:1. Brake hp: 180 at 4400 rpm. Five main bearings. Hydraulic valve lifters. Carburetor: Carter Type BBD two-barrel Model 2259SB. Base V-8 for all except Fury.

(Fury V-8) Overhead valve. Cast iron block. Displacement: 303 cid. Bore and stroke: 3.81 x 3.31 inches. Compression ratio: 9.25:1. Brake hp: 240 at 4800 rpm. Five main bearings. Solid valve lifters. Carburetor: Carter Type WCFB four-barrel Model 24425.

(Optional V-8) Overhead valve. Cast iron block. Displacement: 276.1 cid. Bore and stroke: 3.75 x 3.125 inches. Compression ratio: 8.0:1. Brake hp: 187 at 4400 rpm. Five main bearings. Hydraulic or solid valve lifters. Carburetor: Carter Type BBD two-barrel Mode12407S. NOTE: This is called the '277' engine and came with solid valve lifters when the optional four-barrel 'Power Pack' was installed.

[Jerry]

Is this a 277" or 303"  1956 engine?  First picture shows top of the engine.  Second picture shows water pump, which is 10" across and 6.6" high.  The 3 water pumps listed in local parts houses for a 277" engine do not fit this engine.  Any help appreciated.  More pix available on request.
thanks
Jerry Whitfield
Winston Salem North Carolina