" From: farna@xxxxxxx " " The "S" is for Sport. There may be some different tuning, possibly " different cam, for the 258, but it's just a run of the mill 258. afaik there were only two cams, one for 1bbl engines - which changed little if at all since '64 - and one for late-'70s 2bbl engines, with ~12* more duration. they were used across the board. btw late-'60s 2bbl 232s used the same cam as 1bbl. ________________________________________________________________________ Andrew Hay the genius nature internet rambler is to see what all have seen adh@xxxxxxxxxxxxxxxxx and think what none thought