If it was ME... Yes, another old fart telling a new comer...
You "could" go down the ICV route, but that would mean making a VZ comply with 2021 ADR's...
Or, ask around (experienced tuners) what would it take to make a 304 meet VZ level emissions. That way you know, before spending a cent, IF it's even possible.
Then, get an Engineer on board. Discuss your plans with him, partly because you dont have a choice, and by discussing it with the you are getting them interested in your ideas. If you go to an Engineer part way through the build, his attitude may well be "Can't be done. Engine is too old".
Once you have the Engineer on board, your path is clear. If the Engineer says it cant be done, you could try another, but be prepared for another "Cant be done" answer.