While you're still on a FL license, go to any smog station. All of them - including "Test Only" places - can do a "pre test". No certificate fee, and usually only a little discount for a follow-up offical test, but you can find out how your car as-is will do. You likely don't need the 87 manifold - a euro type cast two piece is OEM, just not to your car, and likely will pass. Tube and chrome headers will not. It's only a visual inspection for things on the official list.
One thing NOT to do is get an official test cold. If you fail, your vehicle is declared a "gross polluter" and must be sidelined or repaired within something like 30 days. No guarantee it will ever pass, and if it doesn't your FUBAR.
I agree with going to Santos. He's a BB member, a dedicated Alfa racer, and one of the best in SoCal. And a nice guy too!
If your son is actually a student he can remain on his FL license as a non-resident student. Just be sure you update his location with the insurance co. Yes, that will likely change your rates, but a major accident could get you canceled retroactively (i.e no coverage at all!). Insurance co's do not exchange data with CA DMV.