i think the hp xr6 was faster because it was lighter than the vct xr6 due to the vct model having that heave a** irs rear end..

ive got the vct engine running in my ed with the vct hooked up to an rpm switch. and with the vct working the down low torque and throttle responce is excellant...
and when the vct switches over the top end pull is strong up to rev cut..
its definatly a different feel compared to the ed/ef engine that was in there..
i havnt had it dyno'd or run down the 1/4 but the everyday drivability is excellant.

Nice work Troyman, very clean.

I think that the vct would be awesome in a lighter body, as said, it was the IRS that slowed the VCT down http://www.trueblueford.com/AU_XR_Specifications.html

With standard camshaft and aggressive tune I think VCT would be awesome, however I am looking at modifying the head and camshaft profile and the workshops I called all seemed to say the same thing, "Won't make a difference"

i will agree with what troyman has done and it would be better in a lighter car....the au vct also got rear electric windows so it does have a weight problem and a few more welds around the rear end aswell but it really only had 4 kw more.....why? au fairlane vct 168 kw! it had a single exhaust like the normal xr6 and the HP xr6...the vct falcon got twin mufflers behind the cat twin pipes out the back....so the exhaust was worth 4kw put that on a normal xr6 and your back to 168kw same as a single exhaust vct.....so you could put a vct motor in stock au and get 4kw gain..and a much more refined engine...but still only 4 kw as the question is about wich head to use.... the au standard head is the best starting point i think....i have them all ported and the hybrid el head took the least work but was harder to find...the au head is more developed and has good valves and stuff already....the vct head had smaller ports(not by much) and was tight around the back of the valve and had steep climb behind the valve....i think maybe the ports are a little smaller to give it more air speed maybe kinda like the plates you put in a 4v clevo head.... i would go the au std head....i wish i never ported my vct head it killed a lot of personality in the engine i wll just have to fit the blower sooner!