Hello aquadalte;
I would imagine a speed of around 170Kts during go-around.
Yes, likely that speed, but only after the Thrust Reduction/Acceleration Altitude which is usually 1500' AGL.
On the go-around, the flaps are raised one step - From FULL to Config 3, for from Config 3 to Config 2. The FMGEC SRS (Speed Reference System) maintains the go-around speed for the configuration until the Thrust Reduction/Acceleration Altitudes, usually 1500' AGL although there is provision for 3000' AGL for Acceleration. The initial SRS go-around speed is maintained until that point - that speed would be around Vapp to Vapp +10kts, (that is not a computed speed - I'm just estimating here to illustrate that flaps are not retracted, climb thrust is not set and the airplane does not accelerate until after the Thrust Reduction/Acceleration Altitude of 1500' AGL).
Aircraft behaviour at the Thrust Reduction/Acceleration Altitude is, - the thrust is manually set to CLB, and, if on autopilot, the nose lowers slightly, the aircraft continues to accelerate and the flaps are raised to the next step, usually Config 1 and then when the speed is above the minimum for Config 1, flaps are set to the Clean configuration. The aircraft then continues to accelerate to 'Green dot', (Max L/D speed - that would be around 205 kts or so but it varies with weight, etc) or 250kts depending upon what is set in the FMC.