A automatic transmission with a shift kit, 4.10 gears, and a chip or dyno tune, you should be able to knock off at least .4-5 tenths will decent traction. With really good traction, like on slicks, it might be even more.
Yes, you'll run with a manual that has about the same power as you do. For the shift kit, I recommend the Jerry mod shift kit. All it requires is removing and replacing a few springs the accumulator pistons and enlarging certain holes in the valve body. For more information, go to www.tccoa.com and read up on their transmission articles for the 4r70w automatic transmission. I also highly recommend a transmission cooler at this point to keep the transmission temperatures down.
BTW, Try setting your 1-2 and 2-3 gears shifts between 5600-5800rpms. You're not making anymore power beyond these rpm levels. You can set the rev-limiter to 6,250rpms like you have so you don't run out of gear in 3rd gear at the track.