May I suggest looking into the Diablo Sport Trinity T1000 tuner. Take it from another guy running the 37's / HEMI / 3.92. The 3.92's are the best stock config but man this tuner rocks!
I just installed the 93 octane tune yesterday and took a very short rip around this afternoon, and I gotta say it's pretty sweet. I was hitting 160 kmh on the back hwys without any work! The shifts were so smooth my wife sitting next to me had no idea what speed I was hitting!
Turning onto the main hwy after, I was hitting 7th @ 100 kmh and 8th @ 120. Folks behind you will just vanish into dust! I honestly thought the guy coming up on me (already on the hwy) as I turned onto the hwy had turned off, until I spotted the speck way back.
PS: If you don't have a local supplier (I say that because you're an ocean away) then FastnUgly @ BP (Bully's Performance) is your man! Give him a PM, and he'll take care of you.