I would never use tubes that I didn't know how old they were. Racing tubes are not cheap being close to $100. each . Trying to save a few bucks could cost you a lot more. On the subject of drilling your new rims. The nut that retains the metal valve stem will cause more damage than the drill bit. Another thing to keep in mind when putting tubes in slicks. The tubes have to be able to move, if you don't use a lot of tire talc the tube will stick to the tire rip. Also, If you put tubes in slicks that have previously were soaped to prevent leakage , all the soap residue needs to be rinsed out completely and dried or the tube will stick to the tire and rip even with tire talc.. Unlike a tubeless tire your tire will go flat within a minute when the tube rips..