Gen II with a 4 sp auto?

I once owned an '84 Ford small-bodied LTD [NOT a Crown Vic] with a TBI [Ford called it CFI] 302 HO engine and an AOD.  It had a 7.5" rear with 3.27 gears and posi, and it would SMOKE a totally stock carbureted 302 LX 'Stang from a stoplight...AND got decent mileage.

Agree'd Short gears in the area of 3.54:1 work nice if you plan to spend time in an area where you drive them 1/4 mile at a time.  Which was pretty much the performance standard when these cars were built one way or another .  Keep in mind that was an era when anything over 3 gears forward was an oddity and a power glide with 2 forward gears was still sought after.
But times change as did design philosophy,
The advantage built into these automatic transmission (and also into things like the World Class 5 speeds) is the acceleration factor was built into using short gears from a dead stop and have them be come progressively taller as you worked the way through them. 
Thus looking at final drive on the late model cars these transmissions came from in general they would be geared for about 32 to 35mph per 1000 rpm in the final gear. '
What does that equate too more or less?  Something like a 3.05 or a 2.90 or close to that depending on the car once you are in 4 th gear in an automatic or 5th if standard. over drive.
That of course takes into account OEM standard tires.
Also the factory Torque converter is going to be loose or the equivalent of a 2200 ish rpm stall converter when equated to our old school cars.
So to emulate that operating condition on say an AMC car.  A 3.15:1 rear end with appropriate tires should end up with about 32 mph per 1000 rpm.  And if you hit a hill or are pulling a load or presume to pass some one it will down shift to the next gear down which is usually 1:1 or straight through gear.
Get muscle car acceleration from a dead stop, 1st is going to be shorter or steeper or what ever you refer to it as giving the final equation of a wide ratio 3 speed with a steep O.D.
Add the stall converter and further deepens 1st gear.
Not that is not a drag race package senario, that is is a street senario and just about every car I have owned was geared that way since the middle 80's.   And as I build and drive street cars I find building the equivalent of that.
I do not want my street car to have  a stump pulling 1st gear.  But over the years far too many people have retrofitted transmission into their performance car from the 70's only to find they ended up with a granny gear and an over drive and wide ratio 3 speed requiring them to start in 2nd gear.
As the transmissions are use in OEM many of them have a 2nd gear start in automatic, and about a 500 rpm change in engine rpm when the torque converter un-locks.
My 904 is set up that way in my Spirit.  With  a 2.51 final drive an p 235x60x14 rear tires and a 2200 rpm lock up converter I have no problem pulling hills, driving in the city or getting adequate performance.  But the automatic does what it is designed to do, down shift as needed.  It also does something else that emulates these transmissions when driving in traffic, there is no low rpm engine braking rolling up to a stop light.  Something that confused the heck out of me when my Olds purchased new in 87 started to do from the get  go, eat up front brakes.
In fact every car I have ever owned from that era on has eaten front brakes.  Ceramics rather that semi- metallics have pretty much stopped that and the wheels stay cleaner.
So I disagree.
I would not choose anything shorter than a 3.15:1 rear end in AMC land and frankly if I had any real reason to assume I would not tear up an AMC 15, I would use it as there is a 3.06 or something like that available.
My Donohue has been running a 5 speed for close to 20 years now with a 3.15:1 final drive and I have absolutely no reason to want to change it.  !st gear is a bit short with that final drive, but there is enough cam in the engine that it makes it better to drive in traffic with 1st that short.
The Hornet I am building still has the rear axle in it that came with the car. It was a 232 with automatic and about 75,000 miles on it and the thing is in good shape.
With the tires I plan on using that works out to about 37 mph / 1000 rpm. I am figuring the V8 that is now in it is good for about 425HP in it's present tune and I think I can get a lot of miles out of it before I have a problem.
As for performance?
The first gear in the 700R4 is short to compensate if you will the taller rear end than one would normally expect to see when doing a conversion.
The Torque Converter has 2200 rpm stall to help those things take place and that is a nice number as close as I can tell.
As a multiple speed transmission, under load it will down shift from overdrive to 1:1 when needed and the torque converter will unlock when the ported vacuum drops as the engine picks up a load.
It emulates and application that GM had it in in the Camero's in those years and I owned at that time an IROC Z28 which was always in the right gear and if it wasn't you tickled the throttle and got it there.
I do not expect to have the car do everything in over drive.
No need for it, the transmissions shifts around picking up loads.
I'll stay with a goal of 32mph /1000 rpm final drive and given a choice, a 3.15 or what is the other 2.87?  That works for the street for me.
And if the final application does not work out, I know where I can pick up a MOPAR 8 3/4 in good shape that will bolt in for next to nothing with 3.23 gears.  Not what I want particularly but will work.