Gnu Radio symbol recovery
Okay, I figured it out myself. I will share my solution. After some googling I realized that this is clock recovery problem, so I used Clock Recovery MM block (with default parameters except for Omega). From Clock Recovery MM

If the input signal pulses do not have peaks (e.g. rectangular pulses) the input signal should be conditioned with a matched pulse filter or other appropriate filter to peak the input pulses. For a rectangular base pulse that is N samples wide, the matched filter taps would be [1.0/float(N)]*N

As rectangular pulses is my case I added Decimating fir filter with taps np.ones(int(samp_rate/baud)-1)/int(samp_rate/baud)
and decimation 1056/4 = 264 and for Clock Recovery MM (which is decimation block) I put Omega = 4.