I've built about 15 pushrod engines by now, mostly domestic, a few import and one rotary. Most of them with forced induction (turbocharged primarily, occasionally supercharged).
Most of them passed emissions in NY, CT and NJ and all of them would be considered "far beyond what is necessary" for the street.
Other than the rotory which was for a friend's car, almost all of the engines were for my projects.
In addition to the above, I've been at least "involved" in building weird stuff.
Two siamesed Buick V6's for a nice 8.2L V12, turbocharged of course, shoved into a Dodge Pickup (heh, heh).
Converted an old GM "car" diesel V8 to an essentially indestructable gasoline engine, which now powers a big sand rail that has lights, tags and is a friend of mine's "sunny day" daily driver.
A 1980 (or so) Dodge D300 crewcab "hybrid". This is a friend's project that's been going really slow for a variety of reasons, but it moves under it's own power finally.
I and several friends shoved a 460 BBF into an early 90's Explorer 4-door. The same friends and I converted an unassuming Ford Taurus into a RWD car and shoved a 351W with a pair of smallish turbos into that. That's a daily driver also.
Yeah, built a few engines ;-)