I transplanted a B16a engine from JDM EK4 into my local model Civic EJ7 a few years back. From what I've read, for EK generation Civic the chassis production method and the material were the same. I forgot to bookmark the website, it's in Japanese, so I used the google translate function. However, for EK9 Type R, the thickness of some parts of the chassis are different. Seam weld were also used in certain section to increase body rigidity.
The engine that I transplanted has only about 60bhp more than the original one, and because the chassis is virtually identical to EK4 Civic, there should be no problem. But just to be sure, I installed some 3-point front strut brace, rear & fender braces, and some stiff rings (like those Spoon Rigid Collars) beneath.