kongo speed caps out of the box. It can mount massive ammount of ammo, but restricting it
a bit 26/44 is doable.

But really not for long. 25/42 is the most used speed if you want some bulge and your .2 belt.

one missing note:

the fuso\ise with 14'' will, later on, go to a max of 40kts OH, and the 16.1'' ones will
only go 39kts OH. This happens due to overweight of crew. Same thing happens with Nagato:
starts with 42kts OH, then it goes 40

yamato has a hard 40kts OH to cap (as shira said), SY has 42, and dunno about amagi or
kongo...

1)All IJN BB except B65 ,Yamato , and Amagi usually have 25knt base speed with all
main turrent and no armor (with or without AA) . B65 is 27knt , Yamato and Fuso/Ise
with 16.1" guns are 24knt , no idea of Amagi , but it seems to be 23knt .
Yamato/SY/B65 usually need 4 BVE +12 engi with LV100+ to cap .Other IJN BBs will
cap with 4 more at level +11(or better) VE engi .

2)Yamato/SY can't fit any useful deck armor to bouce BB shell , even without rear
gun . But they can easilly put 20"+ belt armor , can bounce BB5 shell at 10-25
angle . This is always a funny set , need special skill to play .

3)Montana
Montana have best total damege output in BB5 (even better then some BB6) .

please see Mr. Boom's IJN BB guide which is stickied in this forum.