That 1/4 off of WOT will make a difference.
Another thing that will give you slow et's is to make sure your not rolling into the stages beam too far.
An inch or two deep can slow your ET big time.
Heres some pointer's on staging.
After the burn-out dont rush up to stage, take your time it's your turn they can wait.
Look at where the staging beams are at before you go in so you'll know exactly when you need to start easing in.
Ease up slowly breaking the first beam, then stop, gather your thoughts, take a couple big deep breaths and double check to make sure everything is ready to go I.E> shifter in low, carb not loading up, oil pressure is good etc. Then with yoru foot on the brake torque the motor up just a tad to "BUMP IN" by pumping the brake pedal ever so slightly with firm braking pressure till the second beam just comes on, that way you'll know your as shallow as you can be which will net you the fastest ET and make all your runs and reaction times much more consistent.
Goodluck, Charles