Are the manual transmission (e350) and the automatic transmissions (u241e) interchangeable and what does it entail 2 swap from automatic

The bell housing will bolt right on. You’ll need to change out the gear selector for the shifter assembly (four bolts on the tunnel you’ll see when you take all the plastic off the center console area). You’ll also need to change the pedals and bring with the clutch master cylinder which you will need to figure out exactly where that will need to go through the firewall and drill a hole. If I remember right the axels are different on the trans end. And the mounts are a little different but the automatic vehicle should still have holes to bolt in the manual. I have done this in Mitsubishi, Volkswagen, Toyota and Scion, I’ve found you wind up pulling your hair out unless you have complete donor car to take all the parts you need including bolts and miscellaneous. If you’d like my opinion, find a 02-06 Camry manual transmission, geared better, you aren’t running such high RPMs all the time. That’s why these tCs are so notorious for getting rod knocks. Plus in my 2009 I was running a Camry transmission and consistently averaging 37-40 mpg