There is 2 N/A 4.6L non-stroker 3V Mustangs over 400 RWHP. Both cars are running 11.1 Compression ratio engines with BBR heads and BBR cams. They have Long-tube headers, x-pipe and stinger mufflers. The cars also have pretty much every bolt on as well( CAI, UDPs and CMCV Deletes ). One of them made 411 RWHP, the other was 403. Both of these cars are making better power than the Streetable 401 RWHP JDM 4.9L Stroker N/A car that is being referenced as what it takes to make 400 RWHP.
There is a car from SuttonHP that is very close to 400 RWHP with the stock Longblock. If it got a new 4.6 with the compression ratio of 11:1, it to would be over the 400 RWHP N/A.
IMO, Strokers are not what it takes. There is a lot them out there that are making similar power as similared modded 4.6L cars. I haven't really seen a N/A stroker with a huge power advantage over a stock displaced 4.6L. If Strokers were a great option, JDM's streetable 401 RWHP stroker should be leading the pack, not trailing like it is.
I know JDM's race car has a 3V Stroker in it and it is currently the fastest N/A 3V car. Their race car is also a different car then the Stroker being referenced. I haven't heard how that streetable Stroker car has done in the 1/4 or the 2 BBR cars.
Personally I haven't decided what I want to do with my 05 Mustang GT. A part of me wants a Turbo kit because I have never had a Turbo charged car. I have played with all 3 types of Superchargers though. Another part of me wants a Big-Bore N/A 3V car.
Nobody has tried to see what just a 5.0L Big-Bore would do N/A with a 3V. That would be right up my alley though as I have a 5.0L BB N/A 2V car. As it stands right now, I am the ONLY streetable N/A 2V over 350 RWHP with an Automatic transmission car on 91 Octane pump fuel and I also did it with an IRS and dare I say it, NPI heads.
Seeing how the BBR cars did, I am pretty positive that an 11:1 compression N/A Big-Bore with ported heads and cams and the supporting mods would around the 440 RWHP N/A with a 5 spd manual car. If I choose to go with another N/A car project, my goal would be 450 RWHP.