It sure would have. If they had run 340T/A engines with the four speed new process gearboxes, I suspect the fords and holdens would have had their arses handed to them.
Although, the E49's advantge was that with the lighter 6 up front they were far more nimble in the handling dept. The phase III with it's big heavy engine had a higher top speed, which translated into wins on the Long fast Aussie racetracks. In NZ where the tracks were shorter and tighter the falcons couldn't get a look in. Ford even sent Alan Moffat and his phase III out here to end the charger's domination. He failed. If they'd built the HiPo 340 chargers, they wouldn't have been as sucessful here in NZ as the 6 cyl monsters were. Although motor racing history over there is OZ might have been written much differently.
I think to be fair much of the blame for the Aussie mopars faults can squarely laid on the Aussie Govts local content laws. They were forced to use the grossly inadequte borg warner driveline componentry, which was nowhere near up to the task. And other rubbish like the Email built carter carburators, and alternators. I've also read that the Aussie made pistons used in the small blocks weren't as good as the US ones.
Over 35 years later, the once much unloved mopars are really starting to gain the appreciation that they rightly deserve.