Sca11ey

hey i know this isnt exactly on topic but it has to do with mounting chassis so i figured i'd go to you guys. I bought a pair of mission vsi's off hockey giant and the penetrator vanguard chassis is so heavy(much heavier than the standard 7000 series aluminum) so my question is, If i get the Magnesium Vanguard chassis will my LHS be able to put the chassis in the existing holes (being as they are both the mission vanguard chassis im assuming the bolts would need to go in the same spots) or will they need to put the chassis in different holes so it holds, which would make it be a little off? i know they dont do it the legit way with epoxy