There are no facts to prove that full 3L makes more power than a ported 3L build. There never has been. Just because the 3L you bought is low on power doesn't mean the ported build is the cause for your lower power numbers. I already posted a link showing dyno results that show each build type can vary wildly. A ported 3L can make just as much if not more power than any full 3L build. There are/were quite a few ported builds pushing over 220whp which is difficult in either build type.
The selection SHOULD NOT be based on power output! It should be based on what the installer prefers (2.5L intakes/porting vs. 3L intakes/custom throttle brackets, egr, fuel rail, wiring, vacuum lines, etc)