[Funny]

C64
3.166 2.050 1.481 1.166 0.916 0.815

I am pretty sure that the 6th gear (and all others) in:
C60
3.166 2.050 1.481 1.166 0.916 0.725

are able to fit up.

Hope that helps.
You may want to find a C60 transmission in a junkyard

Wikipedia quote:
6 Speed transaxles

C60
Above 300+whp 3rd gear and Final Drive will break. Gear ratios for this transmission.

1st 2nd 3rd 4th 5th 6th Reverse Final
3.166 2.050 1.481 1.166 0.916 0.725 3.250 4.529

Applications:

2000-2005 Toyota Celica
Toyota Corolla
2003-2006 Toyota Matrix XRS
2003-2006 Pontiac Vibe GT
C63
Gear ratios for this transmission.

1st 2nd 3rd 4th 5th 6th
3.166 1.904 1.310 1.031 0.864 0.725


[edit] C64
Gear ratios for this transmission.

1st 2nd 3rd 4th 5th 6th Final
3.166 2.050 1.481 1.166 0.916 0.815 4.529


Applications:

2000-2005 Toyota Celica with the 2ZZ-GE engine
Toyota Corolla Sportivo (Australia)
Toyota Corolla TS (Europe)
Toyota Corolla Compressor (Europe)
2005-2006 Toyota Corolla XRS (USA)
Toyota Corolla Fielder Z Aero Tourer (Japan)
Toyota Corolla Runx Z Aero Tourer (Japan)
2004-2007 Lotus Elise (North America/UK) (mid engine application)
2005-2007 Lotus Exige (US/UK) (mid engine application)