well, if it's an OE round headlight rabbit, just install them in place of the sealed beams. If it's a square headlight rabbit, then the common school of thought is you need to install the fenders, griller, rad support, bumper (for turn signals) etc to make them fit. I've sometimes pondered that you could probably install the round headlight buckets into a square light rabbit with a little clever ingenuity, then it'd just be a matter of making a grille that doesn't look too shabby.