Why does my Dart hate a 2 step ???

Heres the run down on my Dart.Its a 10 to 1 stroker 408 with Econo W2 heads.Mild 484/510 and 235 duration @ 50 cam .Im running a 750 Demon with a Victor intake and Hedman fenderwell headers .I have an Msd dist ,6Al and Blaster coil on it with Taylor wires.I put in a fresh set of Autolite AR plugs before this meet .I shift at 5800 and go through the lights at about 6100 with the 4.86 gears in the 1/8 at about 93 mph .I am running a Powerglide trans with about a 3500 convertor and the stock 1.76 low gear with a Transbrake.Im running slapper bars and stock springs and 26 x 8.5 x 15 M/T slicks .I run 4.10 gears in it for the 1/4 ,but i was running the 4.86 gears in it at this race since it was an 1/8 mile track ,and i dont have to spur it near as hard to make it 60 foot well with the 4.86 gears.Et's in the 1/8 are usually 7.28 - 7.30 ,with my 60 foots usually in the 1.57 -1.58 range.My best pass of the day was a 7.262 with a 1.54 60 foot with me manually launching on the Tbrake at 3800 and sticking the throttle as i drop the button with no bog what so ever without the 2 step ...