just curious to whether or not anyone knew if this would work.... slight modification needed, heavy modification ?

thanks for any input, Rick

 

In terms of bare bones working, if you did the FULL swap (meaning 3.5 ECU AND 3.5 TCU) then it would work. It is all about how will the automatic shifter, trim, assembly, etc fit and will it mount properly. I know 4th gen manual mounts are bolted to something and 6 speeds are welded to the frame. The example is simply to provide an example of fitment and mount issues. I am pretty sure if you are using the 4th gen ECU then it won't work. I don't think the 4th gen ECU will work with the 5/6th gen TCU (Transmission Control Unit). The 4th gen TCU will not be able to control the 5 speed manual transmissions due to different shift points and gears.

I have not tested any of this and cannot back any of this information. It is my best educated guess and I am pretty sure it is close to right.

 

Also, you say "2003, 2004." 2003 and 2004 did not have the same auto tranny. The 2003 is a 5.5 gen and used the same (albeit slightly different) 4-speed auto we have in our cars. The 2004 had the new 5-speed auto that was used up until the 2007's CVT.