FCI is a good Intake... and to answer your question is Yes it will make little bit of a noticeable gain on top of what you already have.
If you can't afford to have it Dyno Tuned or you don;t want to then just do a lot of research on FCR Carburetor Tuning or just look around on the 450R Forums get an idea. Also Whats your Elevation? This is important. If you do find a guy running your same or similar mods in a lower or higher elevation and you end up using his jetting on your bike it can end up running way worse. Look and see what other guys with Similar Mods are running for jetting in your same Elevation.
What I do when ever I tune a Carburetor I go to a local Motor Cycle shop or dealer, you can also order some OEM jets (take note that I said OEM jets!) because it happens to a lot of guys end up buying a (Dyno Jet Kit) and not that Dyno Jet is bad at all but what I'm getting at is (Dyno Jet) it uses different numbers to size their jets. Example 170 Main Jet (Dyno Jet Brand) is actually equivalent to a (154 OEM Main Jet) so you will run super lean on accident when you think you jetted it up. Also get you a NCVQ needle it's essentially just a YFZ450 and YZ450F OEM needle but will fit any other FCR carburetor.
If the quad idles and you see red hot header pipe off the head then that means your Pilot jet needs to be upped a few sizes (example 40 and it's red hot go to a 45)
If the Quad starts to run way to hot while normal riding or the Header pipe starts glowing bright red hot under "slow/normal cruising" that means the Main Jet needs to be upped a few sizes (most good jetting points for FCR carbs are a 175 to 180 main jet) Lets also mention a LITTLE bit of red hot header is fine for the first 4'' to 6'' inches while you're cruising around.
If the Quad spits and sputters during 1/4 to 1/2 Throttle (under normal cruising speed) that is an indicator that the Needle needs to be Enriched (Move Clip down Lower This allows the needle sit higher allowing more fuel to flow past it)
Tuning the idle Air Screw, make sure the engine is warmed up, you then wanna turn the idle up to a (higher Idle) and then start turning the (Idle Air Screw) out till the engine starts to die, if the engine stalls turn that scre back in about 1/4 or 1/2 turn back in Restart the engine.
A good Baseline I would suggest to start with.
Main Jet - 170-180
Pilot 42 - 48
Leak Jet - 55
Idle Air Screw 2 to 2 1/2 Turns out (or till you hear the engine Idling down with a high idle)
(NCVQ needle) 3rd Clip setting from the Top
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