The US/CA/1937 design

The US/CA/1937 design retains the 8-21in torpedo tubes. The armour deck is increased to 3.5in and the 8in turrets now have 5in on the faces and barbettes. The secondary armament has been modernized to 12-5in twin DP guns with 24-1.1in quadruple AA guns. The ship is flush-decked with a transom stern. They are superior to anything that the Japanese actually built, although they might well have at least matched in not bettered them. This is the Springsharp report:

US/CA/1937, United States Heavy Cruiser laid down 1937 (Engine 1941)

Displacement:
 16,930 t light; 17,582 t standard; 19,250 t normal; 20,585 t full load

Dimensions: Length overall / water x beam x draught
 688.62 ft / 684.00 ft x 66.00 ft x 25.00 ft (normal load)
 209.89 m / 208.48 m x 20.12 m  x 7.62 m

Armament:
      12 - 8.00" / 203 mm guns (4 mounts), 256.00lbs / 116.12kg shells, 1937 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 4 raised guns - superfiring
      12 - 5.00" / 127 mm guns (6x2 guns), 62.50lbs / 28.35kg shells, 1937 Model
   Dual purpose guns in turrets (on barbettes)
   on side, all amidships
      24 - 1.10" / 27.9 mm guns (6x4 guns), 0.67lbs / 0.30kg shells, 1937 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 4 raised mounts - superfiring
 Weight of broadside 3,838 lbs / 1,741 kg
 Shells per gun, main battery: 120
 8 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 4.00" / 102 mm 650.00 ft / 198.12 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 146 % of normal length

   - Torpedo Bulkhead:
  1.00" / 25 mm 650.00 ft / 198.12 m 24.00 ft / 7.32 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 5.00" / 127 mm 2.00" / 51 mm  5.00" / 127 mm
 2nd: 1.00" / 25 mm 1.00" / 25 mm  1.00" / 25 mm

   - Armour deck: 3.50" / 89 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 155,483 shp / 115,990 Kw = 35.00 kts
 Range 10,000nm at 15.00 kts
 Bunker at max displacement = 3,003 tons

Complement:
 816 - 1,062

Cost:
 £8.568 million / $34.272 million

Distribution of weights at normal displacement:
 Armament: 480 tons, 2.5 %
 Armour: 5,276 tons, 27.4 %
    - Belts: 1,635 tons, 8.5 %
    - Torpedo bulkhead: 577 tons, 3.0 %
    - Armament: 779 tons, 4.0 %
    - Armour Deck: 2,222 tons, 11.5 %
    - Conning Tower: 62 tons, 0.3 %
 Machinery: 4,109 tons, 21.3 %
 Hull, fittings & equipment: 7,065 tons, 36.7 %
 Fuel, ammunition & stores: 2,320 tons, 12.1 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   25,470 lbs / 11,553 Kg = 99.5 x 8.0 " / 203 mm shells or 3.1 torpedoes
 Stability (Unstable if below 1.00): 1.12
 Metacentric height 3.3 ft / 1.0 m
 Roll period: 15.3 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.74
 Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
 Hull has a flush deck
   and transom stern
 Block coefficient: 0.597
 Length to Beam Ratio: 10.36 : 1
 'Natural speed' for length: 29.47 kts
 Power going to wave formation at top speed: 60 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: 2.00 ft / 0.61 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  30.00 ft / 9.14 m
    - Forecastle (20 %): 24.00 ft / 7.32 m
    - Mid (67 %):  24.00 ft / 7.32 m
    - Quarterdeck (15 %): 24.00 ft / 7.32 m
    - Stern:  24.00 ft / 7.32 m
    - Average freeboard: 24.48 ft / 7.46 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 127.3 %
  - Above water (accommodation/working, high = better): 168.8 %
 Waterplane Area: 34,312 Square feet or 3,188 Square metres
 Displacement factor (Displacement / loading): 111 %
 Structure weight / hull surface area: 124 lbs/sq ft or 606 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.52
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent