Sweet baby Jebuzz! I had no idea such a thing existed. An ECM free 2UZ, sure would like to drop that in the Tacoma. I'd only need to take it back out every time I did emissions testing and have what... $20K to burn on it?
Well, it depends on where you live. In VA the replacement motor has to be dated later than the year of the recipient vehicle. In my case, a 2002 Tahoe LM7 motor, the last year for mechanical throttle linkage. "Drive-by" emission testing on that motor, on what they thought was the original 4-cylinder 3RZ-FE engine, was actually within the parameters for that originally configured truck. Go figure.
Also, within some states, certain counties require emission testing and others don't. Here in occupied Northern Virginia it is required, but in the neighboring counties south of where I live it is not. Another example, I understand that to be true of Oregon as well from my research.
Those motors are hard to come by. The guy I know who did it for his FJ40 had 2 new crate marine motors, but he was a Lexus engineer with "connections".