I plan on modifying some of my cheap spinnerbaits by upgrading the swivels to ball bearing swivels. what size swivel is best a #1, #2, or #3?

Size # 2 is what is used on 1/4oz up to 3/4oz and some will use it on 1oz as well. I use Worth ball bearing swivels, they aren't cheap but they are better priced than Sampo and they are as good, if not better than Sampo. The best price I found for a 100 count is Barlows because they will let you buy the swivel and split rings separate which saves a good bit but Lure Parts Online has them all ready assembled for a decent price and I believe you can buy them in packs of 10 so you don't have to buy 100.

Size # 2 is what is used on 1/4oz up to 3/4oz and some will use it on 1oz as well. I use Worth ball bearing swivels, they aren't cheap but they are better priced than Sampo and they are as good, if not better than Sampo. The best price I found for a 100 count is Barlows because they will let you buy the swivel and split rings separate which saves a good bit but Lure Parts Online has them all ready assembled for a decent price and I believe you can buy them in packs of 10 so you don't have to buy 100.

thanks for the info man.