I configured my Kongo according to your rules and my top speed is only 20/34...
I got the following setup:
BB1 Heavy Engine
3 Engineers 49,49,43
2 Repairers 43,42
Used the 12,2 guns with 2 normal and 1 ap each.
Then some AA DP guns 2*5" with just 1 AA ammo..
Are my Engineers too low?
0.2 belt and as much Buldge as I could fit without losing further speed (28)
Could throw the AA away, as it's not much use anyway...