I recently changed my ERA from a top loader to a TKO600, with new clutch and pressure plate. I called Brent, at B2Motorsports. I too had an 11" clutch, after replacing it TWICE before the TKO I wanted to upgrade to something that would really hold!
Brent got me covered real nice, works great, even with slicks, the clutch holds!
502-759-1431
http://www.b2motorsportsllc.com/productpage.htm