408 W2 combo - where to from here

Hi guys,

Out here in Australia I am running a 408 / w2 combo in a 69 barracuda. Running a CRT 727 full manual with 3100rpm stall and 3.45 diff gears. Best run to date is an 11.9 @ 115mph with a 1.9 60ft.

Engine specs are:

408 stroker 360
W2 econo heads - standard 260cfm at 550 lift
W2 single plane inlet
10.5:1 compression
750hp Holley
Tti step headers / dual 3" exhaust
Comp 294 s solid flat tappet(248@50' 540 lift once lash considered)
1.6:1 rockers

The car is a street car and heaps of fun, just wondering what people's opinions are on what the next step would be to make it a bit quicker without destroying streetability, some say port heads because not enough port volume for 408 cubes, others bigger cam because w2 heads seem to like more lift, bigger converter, lower gears, bigger 1 7/8" pipes.

Car made 340hp at wheels at 5500rpm then fell away, so maybe 450 to 460 flywheel, wouldn't mind making around 520 to 530hp.

Thanks for any advice.