No, don't use books that are that old. The GMAT has gotten a lot harder in the last few years. Get the most recent books you can. The 2005 versions should be out now and are probably discounted on Amazon.com. If not, check on Ebay for older versions, but don't get anything older than a 2003 edition (with the exception of the OG, which I believe hasn't been updated since the 10th edition. GMAT math has gotten a little harder than the OG, so you might want to get Kaplan 800
for harder math questions).