Gotta laugh when conversation about performance gained by optimising volumetric flow inevitably turns into a CAI pissing contest.
Fact is there's not enough magic in any OTR to waste time and money pontificating which looks best or might contravene an interpretation of a design rule. Just go with an Australian one, FTW.
Seriously, most OTR are built like an oversized 110db plastic trumpet, all are capable of funneling over 1400 CFM. In psychological terms fitting one to a 250 CFM induction system is referred to as compensation.
WTF? Even with CNC-worked & hand finished heads, long duration high lift cam, oversized headers, ported intake and throttle body, the max volumetric flow possible from the latest LS is less than 25% of that!
Its worth noting you can get a 450 CFM replacement dry filter element for the VE for bugger all.
An OTR is not about increasing volumetric efficiency through volumetric flow at all, even the premise that one promotes cooler air assumes you are in a cool climate or on the highway. In my experience the location on top of the radiator for most driving in Australia is second only to mounting directly above the headers in terms of thermal efficiency.
After 100,000k through snow seasons and 47° dust storms running the same OTR as per the fastest VE dragsters, it seems the main tangible benefit is improved air density under certain specific conditions (when there is no heat soak) and a slightly pressurized air pocket (60kph+). Of course I have no doubt about glorious claims of short term gains (by way of repositioning the IAT / MAF) either.
What I've found is a bloody big trumpet on top of your radiator will increase your dyno result and make a shed lot of noise... but if you want repeatable performance under typical road conditions then upgrade your intake manifold, which is by far the weakest link in the LS induction chain over 300 CFM.
