i have a 67 chevelle with drums up front,can i convert to disc using my drum brake spindles.

Yes but they would need to be modified by a machine shop if you aren't real handy with a grinder, drill and tap. More trouble than it's worth if you can afford a conversion kit. If so, the benefit of getting everything in one package without having to search for parts and pieces from multiple sources is a major plus. Been discussed on this site about ten thousand times. (not really, only nine thousand).

The search feature of this site is REAL useful for finding this type of info. So is posting and looking in the "Brake and Suspension" forum of this site. Might consider both.