I was about edit something looks like it got lost in the refresh, hmm weird.

I usually only shift out of 1st at around 3,500 rpm, and go directly into 2nd. Most of the time I never use 1st gear unless going up a hill from a standing start or when driving slow in a parking lot.
The 1st gear is a bit too close to 2nd, maybe a gear swap with an srt6 ring and pinion would help in 1st gears usability.

Do a search for speed innovation, they did a dyno run on a members car and have the dyno graphs posted. That should tell you where you need to be.

I also find the stock clutch is a bit to slippy, making 2nd gear starts a bit high revving until you get use to the clutch. The car could really use a much more grabby clutch.

Also keep an eye out for the 1st gear tsb's on 2004 trannies, they have a tendency to pop out of 1st.