318 from Down Under

Hi, where in Sydney are you?

As for the carb you could try both but since you have a stock converter I would lean towards the 600 Holley. I would also send it to Greg Kuchel @ Carby Tuning Techniques to go through and mod/set up for best operation.

Have you put the Charger on the scales at WSID? My AP5 weights 3400lbs with a full tank of fuel so I doubt the VK is 3200Lbs

If you are interested I have 3200 stall converter.
Hysteric! My 410 VJ Charger came in @ 3050 lbs at WSID but that was with back seat and passenger seat removed, fiberglass race seat, bumpers removed, console removed and no tailpipes!
Last time out it ran 11.4 @ 119mph with a 1.63 sixty foot time.
Yes I run a set of 26 inch high slicks with caltracs and 5 speed manual and 3.91 diff ratio!
It made 391 RWHP when it did those times but now with trick flow heads and a slightly bigger roller cam makes 425 RWHP!
Yes I am in Sydney, Camden Park.