I just learned about another source for slant 6 torque converters. A friend just purchased one through a local long time transmission shop. The shop obtained it from Dacco Transmission. I found a possible website for them... http://www.daccoperformance.com/

It was a model PP1211 special ordered with a small nose to fit a 1966-down crankshaft to a 1968-up transmission. (or what ever year the change was). I'd have to double check but I believe it cost him less than $300 and I assume that included shipping from Tennessee to Minnesota and some profit for the tranny shop here in MN.