a body versus e body questions

the oil pans no problem. the headers depend on the brand. some might be a universal fit (means they fit NOTHING well) but if they`re absolutely new, maybe u can exchange them? ask the owner for the receipt...i would.
or maybe someone here or elsewhere will trade you or buy them from u.
did u get a Schumaker engine mount kit to put the 318 in your slant/6 K-frame?