CAs and SRs come from silvias. googling "silvia history" or "silvia specs" similar will tell you all the power figures and years and models that each motor came out in what
you're going to have to go custom everything. manifolds, mounts, tailshaft, fuel system. if you didn't get silvias there, and are going to have to import an engine anyway, then you may as well just use the 3T because it all just bolts up