408 W2 head combo - suggested upgrades

Hi everyone, i have a 408 stroker in a 69 Barracuda fastback here in Australia and i am looking at stepping it up a bit without totally changing everything,here are some rough specs:

10.5:1 compression,forged pistons,
Forged crank,h beam rods.
248@50 solid flat tappet cam (comp magnum) with around 540 net lift with 1.6:1 rockers.
Mopar w2 single plane manifold.
MSD distributor,6AL ignition.
750 HP holley double pumper.
TTI step headers 1 5/8" to 1 3/4"
Dual 3" exhaust
W2 econo heads,2.02 inlet valves, no port work,valve job only. 252cfm@500 lift,270@600.

Car runs 115.5mph consistently over the quarter mile and is very streetable but i think i have left a lot on the table, especially with no port work, minimal lift for a W2 head and smallish ports for 408 cubes.

Looking for any suggestions for a couple of upgrades that will wake it up a bit.