I'm sure there are other threads out there showing FI capabilities, some have already given good estimations of power, I'd like to focus on one specific situation, that is cam only...So this would be CAI, headers/exhaust, tune, and cam...optionally, you could add an underdrive pulley (probably not worth more than 5hp, but does allow quicker reving)...with the LS3 a FAST intake will also be available, along with a FAST throttle body (102 mm, vs FAST 92mm for LS2), According to FAST, early testing on a STOCK LS3 engine with a Big Mouth 102mm Throttle Body produced gains of 14+ horsepower and 11 ft/lbs of torque at the flywheel over the stock intake. I can guess that when people learn how to port this, on a MODIFIED LS3, you'll start seeing 10-15 rwhp gains.
http://www.streetlegaltv.com/forum/f...-ls3-1908.html
So for a cam only car, lets take the G8 for example, similar motor design, a little heavier, but just to show the potential, here is an Aussie vid of a cam only Holden G8 I'll include links to the mods, but other than a little lightening (which probably would only bring it even with the camaro weight), and running DR and skinnies. Check out the MPH...=power
http://www.g8board.com/forums/showthread.php?t=974
Here is a chassis Dyno of a cam with mild heads, LT's and vararam C6...cam is an LG G6X3...This combination had not been tuned to optimize performance.
http://i139.photobucket.com/albums/q...d/LouisLS3.jpg