Youo've got larger valved heads, larger ratio rockers, and a big wide open intake. These mods are going to put the powerband higher in the rpms and all of these are going to lower the incoming air velocity, which is where you get your power in the low rpm. This is very normal for your setup even if your cam is stock. you could always launch at a higher rpm, but I would look at it as you're just going to have an easier time getting traction now. I doubt a TB or CAI is going to make the power come on earlier, but I will say if you don't have a 65mm TB and 75mm MAF yet get them. You can advance your cam a few degrees however and that will bring the powerband into low end grunt range agan. But it'll drop off your higher rpm power a little. It's a compromise basically, unfortunatly you really can't have both without getting really creative and expensive.
