Looking at your parts list - I may have missed it somewhere - what stall and gears are you running?
Next - power through an auto will always disappoint a bit. My built auto 2v only put down 408 on a mustang dyno but ran 11.45@119 with a 1.67 60 off the ft brake - stall and gears helped a ton (well plus boost).
Another car I built for a cousin - PI swapped 98. Small cms cams, stock pi heads. Accufab plenum - 3:73 gears put down 278 na and 378 on a 125 zex hit. It ran 11.70s at 115 or so. It had a lot of suspension and would yank the wheels and cut very low 1.5 60s.
See how it runs at the track and then decide if max HP vs HP/torque under the curve are more important.