Designer_Mike wrote:...and the 600 drops by 4 mm but the 600 only made 115 hp and the FZR1000 carb version made about 140 hp so I'm thinking the 600 TB would be on their very top end and most likely restrict the HP on my project.
Never mind the horsepower, think of the airflow. What does your bike rev to, no more than 11000, and the 600 must be upwards of 14K, so it's a lot closer than you think. Then there is the restrictions within your standard carb set up, as in the venturi ones, the extra lumps of brass etc that you don't get with the injector set ups which translate to a bigger effective diameter.
Then go back to the horsepower, 34mm on my GTS gives me 118 at the rear wheel with no air box, your carbed FZR1000 in it's prime would only give 125 max and thats with better cams than mine, so the horsepower argument is diminishing. Secondly, a standard GTS1000 has 92 rwhp, and even with no cat etc produces just 100 rwhp, the biggest restriction is the air box and the long inlets. Thirdly, the 39mm flat slides gave 168 at the gearbox sprocket for an 888cc FZR1000 derived lump which hit 14K. Lastly the secondary chokes are used to help tractability with larger diameter throttle bodies (for high revving hp producing lumps), because if a rider gives the bike a fistful in too high a gear the engine baulks, so to sweeten the response the secondary chokes stay closed/open slightly to compensate and then open as the engine/ECU demands, all the time the hapless one is pinning his wrist to the stop. Nearly all race bikes junk this set up.
Conclusion, the 600s will be big enough, they will result in shorter inlet tract lengths and the restrictions will be elsewhere (air box/exhaust).
PS I am curious as to how you are planning to trigger the MicroSquirt on your bike if it is a stock FZR1000 with the B&G code, unless you are triggering off the coils/TCI unit.
I bought a set of throttle bodies and now I'm not sure I made a good choice. 
