OK, as I understand it from previous posts my need for a rebuilt cyl head for 1987 B230 245 head should be: 1990 or newer cyl head, because of stellite faced exhaust valves (I thought sodium filled, but I guess not) combined with an a or b cam (or k) which has a a,b, or k number on the END? of the cam, presumably by timing belt??? with all new springs and all new valve guides and of couse head planed if necessary to straighten or even. Don't know how to number check cyl. head itself if seperated from the engine block or vehicle. Comments???