The "4 Barrel" intake you're probably seeing on e-bay is simply saying it's for a 4-barrel carb. Its "2V" inscription indicates it's proper for 351C "2-barrel heads," which have the smaller intake/exhaust ports than the 4V heads. Most posts I've read from Pantera owners running Aussies say the Weiand Xcelerator 2V intake works especially well (that's what I have). I think technically you can use the 4V intake on Aussie heads but will run out of steam at moderate RPMs. The bellhousing is unique, and even differs between early (-1) and later (-2) ZF models used in Panteras. All the usual Pantera vendors carry these ZFs and bellhousings, or post under Parts Wanted and on the DeTomaso listserv (realbig.com/detomaso).
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