Gosh, it is amazing how much folks feel like you are getting impaled by having your car inspected.
Remember, there never has been a "right" to drive only privilege.

So, it has finaly caught up with Texas, I have been telling you guys for years that this will go nationwide one day.
It won't be long.

Nuttered and such has never been legal anywhere in the US.

I can only speak to Colorado on this one and you guys might suggest that us Coloradin's are bakacwards, but until we had emissions testing here, our air was foul.
I understand that a good portion of that was a result of attrition, older cars getting crushed and being replaced by newer cleaner cars (you know feedback 4.2s). But never the less we breath cleaner air here for it, weather someone blew up their old car and bought a new one or they bought a newer car because they their older one failed. Who cares, it worked.

I can see it always being legal to do engine conversions, provided you go the same or UP in technology, examples:
In Colorado, you can't install an 72 SB chevy in an 84 Jeep and pass.

Only newer engines with newer induction/pollution equipment.
How it is determined is to go through a recert test at a health department garage. These are not revenue generators, they are funded by state tax $. They have techs that HELP you get your rig so it complies.
When I do engine conversions they do the recerts so my customers can go anywhere and pass a test and as far as I know even CA.

Good for Texas!
Just wait, those test parameters will get tougher.

SD