The It/BB/1927 design: obviously inspired by the Cavour

As you can tell, the It/BB/1927 design is inspired by the Cavour. My design relies upon very lightweight machinery to be viable. I use the same 10-12.6in guns. The secondary armament consists of 12-4.7in DP and 24-37mm AA guns. The armour basis is 12in with a 4in deck. This is the Springsharp report:

It/BB/1927, Italy Battleship laid down 1927 (Engine 1937)

Displacement:
 27,857 t light; 29,002 t standard; 30,200 t normal; 31,159 t full load

Dimensions: Length overall / water x beam x draught
 672.45 ft / 670.00 ft x 102.00 ft x 27.00 ft (normal load)
 204.96 m / 204.22 m x 31.09 m  x 8.23 m

Armament:
      10 - 12.60" / 320 mm guns (4 mounts), 1,000.19lbs / 453.68kg shells, 1927 Model
   Breech loading guns in turrets (on barbettes)
   on centreline ends, evenly spread, 2 raised mounts - superfiring
      12 - 4.70" / 119 mm guns (6x2 guns), 51.91lbs / 23.55kg shells, 1927 Model
   Dual purpose guns in turrets (on barbettes)
   on side, all amidships
      24 - 1.46" / 37.0 mm guns (12x2 guns), 1.55lbs / 0.70kg shells, 1927 Model
   Anti-aircraft guns in deck mounts 
   on side, all amidships, all raised mounts - superfiring
 Weight of broadside 10,662 lbs / 4,836 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 12.0" / 305 mm 380.00 ft / 115.82 m 8.00 ft / 2.44 m
 Ends: Unarmoured
 Upper: 9.00" / 229 mm 380.00 ft / 115.82 m 8.00 ft / 2.44 m
   Main Belt covers 87 % of normal length

   - Torpedo Bulkhead:
  3.00" / 76 mm 380.00 ft / 115.82 m 27.00 ft / 8.23 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 12.0" / 305 mm 9.00" / 229 mm  12.0" / 305 mm
 2nd: 5.00" / 127 mm 5.00" / 127 mm  5.00" / 127 mm

   - Armour deck: 4.00" / 102 mm, Conning tower: 12.00" / 305 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 102,385 shp / 76,379 Kw = 28.00 kts
 Range 4,700nm at 15.00 kts
 Bunker at max displacement = 2,157 tons

Complement:
 1,145 - 1,489

Cost:
 £9.061 million / $36.244 million

Distribution of weights at normal displacement:
 Armament: 1,333 tons, 4.4 %
 Armour: 11,305 tons, 37.4 %
    - Belts: 2,869 tons, 9.5 %
    - Torpedo bulkhead: 1,139 tons, 3.8 %
    - Armament: 3,440 tons, 11.4 %
    - Armour Deck: 3,606 tons, 11.9 %
    - Conning Tower: 251 tons, 0.8 %
 Machinery: 2,838 tons, 9.4 %
 Hull, fittings & equipment: 12,381 tons, 41.0 %
 Fuel, ammunition & stores: 2,343 tons, 7.8 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   51,519 lbs / 23,369 Kg = 51.5 x 12.6 " / 320 mm shells or 9.3 torpedoes
 Stability (Unstable if below 1.00): 1.09
 Metacentric height 6.0 ft / 1.8 m
 Roll period: 17.4 seconds
 Steadiness - As gun platform (Average = 50 %): 56 %
   - Recoil effect (Restricted arc if above 1.00): 0.51
 Seaboat quality  (Average = 1.00): 1.12

Hull form characteristics:
 Hull has rise forward of midbreak
 Block coefficient: 0.573
 Length to Beam Ratio: 6.57 : 1
 'Natural speed' for length: 25.88 kts
 Power going to wave formation at top speed: 54 %
 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:  28.00 ft / 8.53 m
    - Forecastle (20 %): 26.00 ft / 7.92 m
    - Mid (67 %):  26.00 ft / 7.92 m (18.00 ft / 5.49 m aft of break)
    - Quarterdeck (15 %): 18.00 ft / 5.49 m
    - Stern:  18.00 ft / 5.49 m
    - Average freeboard: 23.52 ft / 7.17 m
 Ship tends to be wet forward

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 79.7 %
  - Above water (accommodation/working, high = better): 192.8 %
 Waterplane Area: 48,727 Square feet or 4,527 Square metres
 Displacement factor (Displacement / loading): 109 %
 Structure weight / hull surface area: 185 lbs/sq ft or 902 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.52
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent