It's the same chassis, so I would assume it would be pretty straight forward to swap them out.Along with getting the computer and wiring harness etc., from the donor car, swapping in the transmission and differential from the wrecked Si would also benefit you greatly. The transmission in the Si is beefed up to handle the extra power and the Si has a limited slip differential to help put the power down out of the corners (where the EX just has an open diff).