26X8.5X15 or 24.5X8.5X13

My question is i have a 2470 lb hatch with me in it and i was woundering witch tires are going to help me run a faster ET. and MPH..

Im only asking this cause i have mickey thompson that are 235/60/15 witch are equiealent to 26X8.5X15 and the car pulls hard in 3rd but slam it to 4th and it feel slugish almost like a smaller tire would work better but no hook as good.

Car makes 590whp & 409ft TQ. on 25psi on a GT3767S T3 .63 A/R on a dyno dynamics dyno reving to 9100rpm

motor
dart block
gsr stroke
85mm je's 9.4/1

b16 head
crower valve train
crower cams

b16 tranny
ACT 2900 w/ 6puck

 

i am partial to mand h's.
24.5 x 8.7 x 13
26"s are too tall.