Try the following. They make underdrive pulleys and brackets. I have some and they're nicely made.
MARCH PERFORMANCE, INC. • 6020 HIX RD. • WESTLAND, MI 48185 TEL: (734)
729-9070 • FAX: (734) 729-9075 • EMAIL:
info@marchperf.com.
http://www.marchperf.com/