weak compared to.....? lol4.6 is a weak motor, I wouldn't waste your time trying to prove a point NA, you'll only embarrass yourself
Not many cars will push 450WHP on a stock engine coming from 260WHP. AN almost 200WHP jump over stock is plenty strong. Additionally there is NOTHING any other car has done that the 4.6 hasn't. It is an old engine.
As for "well over 400 HP", to the crank, sure. With heads, cams and all the accompanying mods, you would be lucky to see 390WHP.