And for external balance.

The counterweight appears to be removable, so perhaps it could be neutral balanced...

And on that subject, I can't remember which configurations were externally balanced. 428? (Time flies and the memory fades)

I don't see any weights advertised.
Am I overlooking it?

I've never owned a set of street tires that I would trust over 130. "Back in my foolish youth" nor now.
I have been 140+ on drag race tires, for those brief blasts.
Decades ago I knew a guy who ran a "Nascar experience" business. I dont know for sure, But I am pretty certain (If a student passed earlier stage "tests") they usually paced those guys to a maximum apx 110. I drove one to about 120 on the old hard tires and wont hesitate to describe the ride as terrifyingly loose.

An old story I love. Probably well known by most Mustang/Shelby fans.
Carroll Shelby oversaw a prototype '67 car build with a LeMans 427. Super Snake. So rare that the official clubs and registries strongly argued it never existed. The debate lasted for decades.
When someone rolled out and claimed this was the car and showed it, they were outright mocked.
Until Carroll himself saw it.
He said "yep, that's the one!" And told the story of being clocked in testing driving it in excess of 160 MPH.
Not really a prepped race car. Basically, a production GT-500 on skinny bias-ply tires. He said they filled them with nitrogen and jacked the pressure to 60 PSI.
I personally am of the opinion that even if slightly exaggerated...
They must have grown the avocados in jumbo size in Texas! That is insane!

Got it!
Thanks for the notes and discussion Dan!

Thanks again Rory.

I have seen the dual pump setup similar to that, though I think it was usually "redundant" as a fail safe.
Certainly overkill on volume capacity.

One trick to backward engineering the PCV system onto this thing is vacuum port availability. There is one large port on this vintage manifold and piggybacking power brakes and PCV is generally not the desired path to take...
So I have to examine the situation and come up with something creative.

Excellent info Heo!
I think I had seen a chart of the plates before, but not the dimensions. That is very helpful!

And I am in full support of services as provided by Farron Rhodes (sp?) but... You would have to know me:
DIY to extreme. 46-year mechanic experience specializing in advanced diagnostics, drivability, etc. And there is not one thing other than paint that has been worked on by anyone but me on this particular vehicle. And that was butchered.
Knowhatimean?

I like those. always had a soft spot for them. Of course, the fastback style Fairlanes too, but the body like this has so much potential for coolness.
A friend had one with a 427 in it back in about 1978-9. Don't now what happened to it.
 
That windshield is just not correct though...