Yea, I have a buddy who tinkers around with s12s. His words on the CA20's bottom end... "the rods are so weak they bend of their own free will at anything more than about 200hp, and not very far after that, its the block itself that goes." The CA18DET bottom end is MUCH stronger than the CA20Es, or the CA18ETs. My advice is stay away from both of those. For more information on that setup, Check out www.club-s12.org
*ninja edit* That same guy has 3(!) FJ20 engines, and I'm sure he could be persuaded to part with one if your interested.