600 with a CJ should be easy.
What does the Pantera tag mean that says advance is 16 degrees and idle speed is 1,000 rpm? You do have that tag, do you not?
I never had this car new, so I don't really know what it idled like new.
Since the Pantera was an import, it wasn't required to have the same emissions equipment as the Mustang did with an air pump.
It also has headers with dual exhaust and no exhaust balance tube like the Mustang does.
This effects the idle rpm and the idle quality. Makes it a little rougher, so to compare the 73 Mustang and the 73 Pantera, all things are not equal.
The Ford Muscle Parts carb recommendation for a 351c was the 4781, 850 double pumper. Said it was good for 15hp gain.
Having run the CS Shelby intake and the Edelbrock Torker on a Boss 351 in a Mustang, the intake of choice to me was the Torker.
I ran a 4779, Holley DP, and the Shelby manifold did not like it. the Edelbrock loved it.
Personally I think that a 2x4 Holley vacuum secondary carb set up would respond to the best of both worlds.
Keeping the engine vacuum up in a big port Cleveland is very helpful and makes the engine pull hard at all rpms. Too bad this never came to be with a Cleveland?
Works really, really well on a 347 with two 600cfm Holley 1850s.
Also ran a Boss 302 780cfm Holley and a 735 428 CJ Holley on the car. Neither was worth the effort.
Didn't try the Holley Track intake back then but seems that was a true hp gain and held the key to flow vs. velocity?
The first CJ hydraulic cam actually is a very decent cam for everyday street driving.
As George states, everyday drivability suffers with aftermarket cams of that era.
The CJ cam will also reduce the valve train wear that you will get from a higher lift cam.
The combination on that cam doesn't exist for no reason.
For it's idle quality alone, the CJ is worth putting up with it's upper rpm limitations.(about 6,000rpm +/-)
A good carb match for it would be a Holley 1850 600 cfm carb. That's all a stock 351c CJ needs.