power to weight is not as important as trying to launch a 6-speed.
do you know if the 5.0 was auto ?? if it was, the ONLY thing that you could have done to be more competetive was to have been running an auto in your Challenger.
if the 5.0 was a 6-speed, i'm sure you BOTH would have had launching issues, which would have been much closer.
but yeah, 5.0's even give 392's fits so don't feel bad.
2012 RT Challenger Plus.......................2011 IE Challenger