Build thought

You need to remember that your Car irequires a State Inspection, If you are looking for 550RWHP (That’s not calculating in the approximate 20% loss you will incur in your Drivetrain, so you will want, ultimately- a 660HP (Gross HP) Motor @ the Crank. Had you said 350RWHP, it could be done without such drastic monetary$$$ and drivability issues..
In addition to a Steel Crank, Studded 4 Bolt Mains/Girdle and Shot Peened
H Beam Rods, Floating Wrist Pin - short Skirted Forged 11:1 Pistons, Internall balanced reciprocating assembly- you are going to need some very good flowing Aluminum heads, to get the flow you’ll need, to do it right- Ported and Polished Heads & Intakes on a FlowBench. Port matching. Some fairly radical high lift & Duration Cams matched for the purpose, Springs, Retainers, Keepers, Severe Duty Valves, you’re going to be hard pressed to run that much HP & Torque in a broad range that you can run on the Street, and with a small Cube Motor, even more difficult. It’s absolutely possible, but you’re going to need to spend a lot of $$, run around 45-50ish lb. injectors to get you there, meaning a highly enhanced Fuel Pump and Regulator, some large diameter Long Tube Headers to match your larger Ports, Exhaust, and an upgraded Cooling System. Then, your Clutch & Flywheel need to be upgraded, Transmission(?), and the list will continue to pile up...A 4V Cobra Motor & CPU/Harness May be easier, or a Dart Block with some real Cubes- would really help..You’re talking HP ranges that will take out every weak link in the drivetrain out as well.
That’s really just the tip of the iceberg. Your Best bet is- to go Non-Normally aspirated. Then you can run it on the Street, not worrying about barely idling at 1.100, then HP ‘Flat’ until you hit the 3,500-7,500 Powercurve. There’s a kit that can get you close to your Target range without revving the Motor to oblivion, modifying....everything. This Kenne Bell kit might just interest you. If not- some interesting reading just the same. It makes 460RWHP on Pump Gas, Stock bottom end. You can step it up a notch with some Higher Octane, at the Track, run a smaller Supercharger Pulley and you will be sitting at 504HP+ (NET) and 521 Ft/Lbs of Torque. with power coming on in droves very early (and all the way through) the Powerband, 1,500RPM’s was over 350Ft/Lbs of Torque- at the Medium Pulley size Boost level. The STOCK 02’ Motor- boosted- made 450RWHP at its reliable- boosted Pump Gas level Octane. Remember- this is a 245HP Motor, with HP about DOUBLED (with Pump Gas-nonetheless)- with this Twin Screw Kenne Bell kit. Stock Internals..That’s INSANE!
If anything- I’d call it AMAZING!! You will still need to verify your drivetrain can handle this- but much less Motor preparation. Computer Tune is made for the setup, everything needed comes with, no guesswork.Link below, pls let me know if it doesn’t work..KB will give you a waiver for your Inspection.
So, if you’re bent on keeping your 2 Valve Motor- this is a highly viable option. If the Motors got some serious miles on it- by all means- give a call
to Kenne Bell & let them know your plan, they will suggest a plan to yield your best bet with it, and will provide a Tune with it- keep them in the loop & build it with some stout, Forged goodies, and they will offer suggestions to help you make this exactly what you want. But I don’t believe you will replicate a Superchargers reliability & broad HP/Torque (Driveability/reliability) benefits with a normally aspirated build on that Modular SOHC 2V 4.6L with your generous 550HP NET target. I’m NOT saying it’s a bad Motor- it’s a VERY GOOD Motor. It’s just pushing the boundaries of its intended design, is all. I don’t want to see you or anyone sink serious Coin into something without getting what you desire, reliably. I do- whichever route you take...wish you the best of luck! Cheers!! John
http://www.mustangandfords.com/how-...rades-kenne-bell-twin-screw-supercharger-kit/

I’d do your flavor of forced induction first (supercharger or turbocharger). The delimma is that a forged rods / piston / crank will make the same power you have now but cost you several thousand dollars.

The stock motor can support 400rwhp - why not add 100 rwhp now by adding some boost for the same money?