The torque dip at about 3800rpm is bad enough, you want to create another one? Dual stage v-tek?
I read somewhere that the stock car is made purposely with the torque dip because at low rpm=better mpg and at a track at high rpm, you would never go below 4k.
My guess would be play with the timing and take some advanced timing out.
Oh and trying to get that pull at low rpm and with a small displacement motor... don't expect much.