I don't know about the ca20 engine fitting, but the later laser tx3s had the 1.8L BP turbo engine, or the 1.6L turbo. I was considering a transplant of the BPT to my girlfriends old 1985 mazda 323, and from what I found it was a reasonably easy swap, made easier that they are the same chassis. Output is 100kw for the 1.6 and 117kw for the 1.8L.
Hope I shed some light on that for ya.