ziggs, the CHI 3V's (185 or 218cc inlet ports) come with free spacers to fit a normal manifold. Extra $500 not required.
CHI have just released their alloy 2V. All stock 2V parts fit like a normal iron head. These flow 300cfm at 0.600 valve lift and will support 600hp. You can buy a fully assembled set for only $2650. Remember hardened valve seats, pedestal machining for studs, bronze guides, port/polish, CC chambers, etc etc plus....SS valves, teflon seals, quality springs, retainers & locks - and labour to set them up. Price all that up and tell me what you get
There's no way you'd be able to get 2V irons ported and polished to flow that much or cost that cheap!! You then have all the other advantages of light weight, better thermal qualities, run more comp, better CC's etc etc. They also make a much larger torque curve too.