The J/CA/1941 has just a very small improvements

The feature of the J/CA/1941 is an improved AA armament. The secondary armament is now 12-5in DP guns in twin mounts. The light AA armament is a non-standard 48-57mm AA in twin mounts. The rest is the same as the J/CA/1937 with still lighter machinery. This is the Springsharp report:

J/CA/1941, Japan Heavy Cruiser laid down 1941 (Engine 1947)

Displacement:
 14,851 t light; 15,454 t standard; 17,300 t normal; 18,777 t full load

Dimensions: Length overall / water x beam x draught
 687.89 ft / 682.00 ft x 64.00 ft x 23.00 ft (normal load)
 209.67 m / 207.87 m x 19.51 m  x 7.01 m

Armament:
      10 - 8.00" / 203 mm guns (5x2 guns), 256.00lbs / 116.12kg shells, 1941 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, majority forward, 2 raised mounts - superfiring
      12 - 5.00" / 127 mm guns (6x2 guns), 62.50lbs / 28.35kg shells, 1941 Model
   Dual purpose guns in deck mounts with hoists
   on side, all amidships
      48 - 2.24" / 57.0 mm guns (24x2 guns), 5.65lbs / 2.56kg shells, 1941 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, 16 raised mounts - superfiring
 Weight of broadside 3,581 lbs / 1,624 kg
 Shells per gun, main battery: 120
 16 - 24.0" / 609.6 mm above water torpedoes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.50" / 89 mm 450.00 ft / 137.16 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 102 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  1.00" / 25 mm 450.00 ft / 137.16 m 20.00 ft / 6.10 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 2.00" / 51 mm  2.00" / 51 mm
 2nd: 2.00" / 51 mm       -         -

   - Armour deck: 2.00" / 51 mm, Conning tower: 4.00" / 102 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 187,554 shp / 139,915 Kw = 36.00 kts
 Range 12,000nm at 15.00 kts
 Bunker at max displacement = 3,323 tons

Complement:
 753 - 980

Cost:
 £9.548 million / $38.190 million

Distribution of weights at normal displacement:
 Armament: 448 tons, 2.6 %
 Armour: 3,048 tons, 17.6 %
    - Belts: 1,045 tons, 6.0 %
    - Torpedo bulkhead: 333 tons, 1.9 %
    - Armament: 428 tons, 2.5 %
    - Armour Deck: 1,185 tons, 6.8 %
    - Conning Tower: 58 tons, 0.3 %
 Machinery: 4,633 tons, 26.8 %
 Hull, fittings & equipment: 6,722 tons, 38.9 %
 Fuel, ammunition & stores: 2,449 tons, 14.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   18,902 lbs / 8,574 Kg = 73.8 x 8.0 " / 203 mm shells or 2.1 torpedoes
 Stability (Unstable if below 1.00): 1.16
 Metacentric height 3.4 ft / 1.0 m
 Roll period: 14.6 seconds
 Steadiness - As gun platform (Average = 50 %): 56 %
   - Recoil effect (Restricted arc if above 1.00): 0.81
 Seaboat quality  (Average = 1.00): 1.13

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.603
 Length to Beam Ratio: 10.66 : 1
 'Natural speed' for length: 26.12 kts
 Power going to wave formation at top speed: 61 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 5.00 degrees
 Stern overhang: 3.00 ft / 0.91 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  33.00 ft / 10.06 m
    - Forecastle (20 %): 25.00 ft / 7.62 m
    - Mid (50 %):  25.00 ft / 7.62 m
    - Quarterdeck (15 %): 25.00 ft / 7.62 m
    - Stern:  25.00 ft / 7.62 m
    - Average freeboard: 25.64 ft / 7.82 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 155.3 %
  - Above water (accommodation/working, high = better): 135.7 %
 Waterplane Area: 32,017 Square feet or 2,975 Square metres
 Displacement factor (Displacement / loading): 109 %
 Structure weight / hull surface area: 119 lbs/sq ft or 579 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.94
  - Longitudinal: 1.74
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent