I dont think there is one, but you could call Toyota Auto Parts (TAP) out in California & they would know. The # is 916-631-7100 or 1-800-765-7100
on the celica forums i have read of someone doing so on there late 80's celica using a LS1 tranny with a the bell housing changed. im not sure if i can find it again but ill try finding that topic if it still exist. i do know though on on the pirate 4x4 somone long time ago did it for a nissan pickup.
why would you want 6 speed? just to be different? (just curious) probably use a t56 (forget what it came out of)..and have a shop make you an adaptor plate. you'll probably have to get custom clutch setup too though. money will make it work.
No it will not bolt up. I read somewhere that it has its own bell to transmission bolt pattern. I believe it was on Yotatech or Pirate. James