Multimatic shop knows suspensions and those guys know a thing or two about racing that's for sure, not to mention building the Ford GT (for Ford). so I am sure it will be a trick suspension.
But frankly given the almost equal weight between the last gen Z/28 and the new ZL1 1LE, yet the latter's huge power advantage, I'd attribute the 3 seconds at Milford mainly to the latter. I'd also like to hear what a std ZL1 would do there with ZL1 1LE rubber. Something tells me the delta might not be that big