Can Kimber 8TC be converted to biwiring?

While the answer to your question is Yes, you do not want to do that. What you want to do is buy unterminated 4TC, should be very reasonably priced if you search , then have your cables reterminated with 8TC for the bass and 4TC for the mids/highs. Then my friend you'll have really smooth sound. Good Luck.

Yes. Any kimber dealer should be able to reterminate these for you.