differance in p/s or manual heders?

what is the differance in headers offered for manul steering compared to p/s cars for mopar a bodies? what makes the differance? 1973 swinger 318 here. have some old super comps, that slip apparts. but look like a very tight fit around pitman arm/inner tie rod? know there is listed of diffenaces. but couldn't tell what by a book?