Do you live in CA and do you want it to be smog legal? If so, the 3.4 is way harder to do than a 4.3 from what I hear. I know my buddy did a 3.4 swap and did it once for the refs to sign it off, pulled it out and did it again to make it right... He was replacing a 22re so that may make a difference, but I'd definitely spend some major time either talking to a ref or researching all that. I hear the 4.3 swap is pretty basic
