Well in all fairness the early 4.6's had about the same peak output as the 5.0 but less TQ due to the smaller displacement. The T-bird was also hefty compared to a Stang.. well over 4000lbs, and it would have come with towncar gearing.. 2.73 or something stupid. All totalled they were pretty sluggish unless you got the XR version. This is probably why GM dropped the 305 in the Camaro/Firebird line, just not enough motor to deliver proper sports car performance given the weight of these things. One thing I have to give GM credit for is proving you don't need multi-valves and overhead cams to get really high output from a V8. Maybe there was some heavy Cosworth influence at Ford at the time or something.. but every hotrodder in north america already knew this so why did Ford drop the pushrod motor and develop a complicated OHC monstrosity when all they really had to do was offer some updated cylinder heads and induction for the existing platform. Bolt some AFR heads on a stock 5.0HO shortblock and you got 400hp, but it takes a blower to get that kind of output from the 4.6, and it won't fit in every engine bay. It's too bad, probably would have put the company even further ahead right now if they'd gone that route.