looking to swap drums on my 71 convt. to discs, would like to know if other chevelle , monte, or elcamino parts swap directly or does spindle need machined& where is best place to find "step by step " directions?
thanks

lots of posts on the subject on this site.

68-72 GM A-body should swap out as a whole. There are lots of kits available nowadays for <$500 that include everything you need for front swap.