YotaTech Forums - Big Tranny Question ?

I'll try to break this into smaller parts of possible incompatibility, because there is a lot to this simple sounding question.

Bellhousing - > Since the engine isn't different for STD vs AUTO, they should bolt up. Provided you are using V6 to V6 or I4 to I4. I don't know for sure if V6 to I4 (or vice versa) has the same pattern.

Cross Member - > Again the frame is the same regardless of transmission, so as long as you maintain the cross-member with the matching trans, you should be okay.

ECU - > ECU part numbers are trans specific. You can try to use the A/T ECU with a M/T, but the information may not be compatible. You might be able to re-pin the harness to make it work, or you might need to swap ECUs as well.

Driveshaft -> These are usually trans-specific in length, so again as long as you had the corresponding DS you should be okay.

"Clutch system" - > Provided you are using similar motors ( 5VZ to 5VZ) then you would buy the appropriate flywheel, clutch kit, and slave to use in your newly installed M/T. if you are using a V6 trans on an I4 or vice versa, you may have to pick and choose between V6 parts and I4 parts or score the correct bellhousing so you have enough room underneath for all your parts. You'll also need to run hydraulics from the slave to the master, depending on your states inspection process you might be able to get braided stainless fabbed up, or bend your own hardline.

The pedal assembly will switch as a unit, there are threaded bosses for the clutch master cylinder already on the firewall, if you want it to be pretty you'll need a corresponding center console, and various odds and ends may or may not make the switch i.e. cruise control might not work.

Anything is possible with the right tools and deep enough pockets.