The base speed should be 23 kn, and 39 kn OH (with speed cap attained).

You should normally be able to reach that with your six engies, provided they are close to each other in terms of level and vets / experts (boosted and 100 vets).

Take the bulge off and see what speed you get, with those engis you should be able to reach the cap, as Eric said. 60 bulge sounds a bit low though, while I might be mistaken, I thought an L2 could run at 39 with 200+ bulge. I could be wrong, but it may be that your engis simple need more experts and vets.

New EBBs are not being released during this event, keep your eyes on the test forum area for news about them though.

At full displacement your L2 can go 21/35 knots.

At non-full displacement you can go 22/37, 23/39, etc.

It is up to you to play either 2-gun setup or 3-gun setup.

Generally 2-gun AW setup has more advantages in GB.
Pros:
1) Except for MN BB6, IJN BB6, SN BB6, USN BB6 and SN BB5, USN BB5 shooting from full-degree, no bb can effectively damage you with HE shells (no ship-tuning items considered). If you rush with your SW teammates (e.g. PBB teammates), your enemies are very likely to spend time in hesitating which target to shoot first and whether to switch to AP shells, which buys you (and your teammate) more time and more chance. In this sense, an AW ship strengthens your team really. Rule of thumb: as AW ship, try to always go with your non-AW teammates.

2) More error tolerance. Even if you are blind you are able to take considerably more rounds of damages than 3-gun setup L2.


Cons: 
1) Relatively weaker firepower (3 salvos to sink BB5, 2 if lucky; 4 to sink BB6, 3 if lucky).
2) Low speed. 

22 knots cruise speed is ok for the L2, somewhat average.

60 bulge is not that much to considerably reduce your speed.

The 3 lvl 100 18" should give you an OH of around 37-39 knots.

Benser33, L2 cant run at 40 knots with 200+ bulge, youll need at least 8 lvl 121 EB full VE engineers to even get close to 37 knots with that much bulge. 

What people shouldn't forget is that the max OH speed is fixed for each base speed. So with 21 knots base, you can only go 35 OH max, for 22 it is 37, 23/39, 24/40, 25/42, 26/44, 27/45 etc. This is "hard-wired" into the game, and no amount of engies / vets can change that.

Your base speed is a function of your ship's weight (# turrets, armor, weight of crew...) and quality of your engies.

My own L2 reaches 23/39 knots with the lvl100 guns with 4 binds HE/1 bind AP, even with only 5 of my 6 engies lvl 100. All sailor slots are filled, and I can fit up to 47 bulge before losing a knot. That is probably due to the fact that my repairs are lighter, as unfortunately they are not yet at level (only between 90 and 94).