It wasn't always that way in Florida.
I was born & grew up in South Florida, and I can remember going to the state inspection stations with my parents in the late 60s-early 70s. I can't remember if emissions testing was part of those inspections. However, I was stationed at MacDill AFB in Tampa, when I was in the Air Force, and I can remember taking my car for state emissions testing around 1989 or 1990.

I don't think I have any shots of the underside of JagZilla, but, you can at least see a couple shots of the resonators here:

Garage - JagZilla by JagZilla | JaguarForums.com

 

my dad bought me my 1965 AH sprite in1978 they had inspection still
it was so useless...
a guy knew a guy and it got a sticker...
the horn did not even work ( bad horn button )
I had it fixed in 5 minutes

and it had headers, straight pipe, a resonator , and Monza tips...




no they never did exhaust testing... in the state and inspections went away soon after that






or this one

 

My memory isn't what it used to be, mainly because of my mantra when I was a teenager in the 70s: "Better living through chemistry". However, I knew that I distinctly remember requesting leave from my First Sergent in order to take my Turbo Dodge Shadow to an emissions testing facility, and have a sniffer shoved up its a$$, so I was thrown off when you said there was never emissions testing in the state.

A quick Google search reveals that we're both right. Emissions testing wasn't required throughout the whole state, but, it was required in the more densely populated areas:
"As a side note, back in the 1990s, Florida required emissions testing in major metro areas like Miami, Tampa and Jacksonville."

I have the 2-1/4" into dual 2-1/2" Monzas (your 1st link) on Jagzilla. The 3" outlets would be louder and deeper, but, in my mind, such a change in tonality would make the car sound more like a V8 than a V12. As with anything, I may very well be wrong about that theory.

 

My Bad on the Emissions testing...
I do remember that you are right, and that we just missed the cut... on air quality... so we never here...


2-1/2"
Yeah, I do not want it sounding like all the Mustang Gt's around here


omega3 for the memory... make sure the ratio of omega3 to omega6 is at least 2 to 1

 

well,
rehearsal... went... ah..ok..
daughter to Birthday party with her wheelchair
My wife drove the XJS the first time to her work...
Performance Saturday night went Well!!! Yeah!...
(got the jag back and dropped the van off on the way...)
Nothing like a man in a TUX driving a V12....


Sadly al dressed up and no where to go afterward (wife was working)


[begin joke;]
I think I need to make a sticker (magnetic of course) that says
"have grey poupon, will travel"
[end joke;]


took the long way home from Messiah rehearsal and ran her on the interstate dropped down to 2nd for some 50 to (on up there runs...) to blow some carbon out...


I might schedule some injector rebuild time during the Thanks giving holidays...