Re: 11 CB350's and 360's. And so it begins.
VM32s are still too big for a CB750 (it has four cylinders). 30hp per cylinder on a CB350 would be almost double the hp. I suppose it's possible, but it's very, very, very unlikely. You would have to drop tens of thousands into the bike to get that kind of power out of it.
It's academic, but it would make for an interesting discussion. In my opinion, the best way to achieve that level of power on a 350 would be to go with a forced induction option (turbo, supercharger, or nitrous). All of those options don't generally require larger diameter carbs, though, so lets set those aside for a moment.
To get 60hp out of a naturally aspirated 350 it's going to come down to revs. Horsepower is mathematically calculated based on torque and rotational speed of the crank. HP = (RPM x Torque) / 5252. To get the highest possible power out of an engine we want the torque to be highest at the highest possible RPM (this will make the bike unridable, or at least very little fun to ride, but ignore that for now). Peak torque occurs when an engine is operating at its highest volumetric efficiency (most fresh air and fuel in the cylinder, per cycle) and any parasitic losses (pumping, drag, etc) are kept to a minimum. Peak HP occurs at 10,500 RPM and we can calculate out the torque to be 18ft/lbs at that point in the RPM band. It's a simple matter of altering the formula to decide what to change in order to achieve the required HP goal.
For instance, lets say we want to hit 60hp and we can keep the torque at 18ft/lbs and the parasitic losses even throughout the RPM range (impossible, but bear with me). Our formula now changes to 60 = (RPM * 18) / 5252. Solving for RPM gives us a goal of 17,506 RPM. Now lets assume we can increase the volumetric efficiency in the upper RPM range and increase torque to 20ft/lbs. Now we only need 15,756 RPM in order to hit 60hp. Still damn tough, but certainly more possible than 18K.