block hugger headers or manifolds

well i have the schumacher moter mounts they are brand new so that wouldnt be an issue. well the headers that i got were for a 72 duster that i have with is a slant 6 swap to, i had the same engin and the headers fit that car but i know that the moter mounts are diffent. i used the schumacher moter mounts on that car and did not have a issue whith the headers