Do you guys like the fast ratio P/S steering on your TA Challenger or AAR Cuda? I just don't like the lack of road feel on my AAR. It almost feels unstable at higher speeds also. Could part of this be due to my front end alignment?

When I bought my current 70 cuda the front end was really unstable under hard acceleration. Turned out to be a miss-adjusted front sway bar.
Later I installed a fast-ration pitman so speed up the slow and loose steering. IIRC 3.5 turns LTL became 2.5. BIG improvement.

Most any maneuver now does not require a hand from leaving the wheel if I so choose. Not the way it used to be!!!!

I highly recommend putting offset UCA bushes in the car to increase caster as much as possible for high speed stability, make sure your alignment is correct to today's tire types etc. good shocks are a must. This in itself should improve feel at speed, from there you could install fast ratio pitman and idler arms to reduce turning movement of the steering wheel however it won't make the "feel" any better or worse. You could lower the pump pressure a little to make it slightly heavier to turn the wheel however increasing caster will also make the steering slightly heavier as well.
I have done all of the above on my Cuda but added a stage 2 steering box from Firm Feel and at 110 my car just sits flat on the road and I love it

Fast or standard ratio, not really crazy about it.

For me most of the problem is the thin, oversize steering wheel and being used to a daily driver with modern steering.

I know a tuff wheel would be a big improvement and should have come with AAR and T/A's. Cars would be more appropiate to their intended purpose.

*Edit* That just made me think of one of the road tests on (an AAR, I think) one and they described the slalom course Driver as "sawing at the wheel".

The 'thin oversize steering wheel' is certainly a factor, but minor in comparison to the 3.5 turns LTL.
I too converted to the Tuff Wheel, and I also reduced the PS pump pressure with shims (you can only go so far with that mod, and its pretty slight).
Offset Moog bushings too. And 235/60/15 front tires

But it all adds up. The fast ratio pitman makes the biggest difference. At slow speeds its a joy, above about 75 is can feel pretty 'darty' but these aren't exactly slalom cars.

A firm feel 2 or 3 box would be great, but I am happy where I am at this point.

IMO, two separate concerns.

Road feel is typical Chrysler over assist. You can change the pump to a modern unit or reduce the output of the stock pump to improve this.

High speed instability can be a result of high speed combined with a fast ratio, but usually not at highway speeds, but rather is the result of the alignment. Not enough caster will cause this although that is assuming tire air pressure, shocks, springs, etc are all set up properly and performing their jobs correctly. Steering wheel diameter also plays into this. But, stepping up positive caster will help.

While you are improving positive caster, also add some negative camber too. Radials, if in use, can use much more aggressive alignment specs than a bias ply, which is what the original alignment specs were designed for.

If after those changes, you still feel it is too unstable, then you could consider dumping the fast ratio arms for standard arms to slow down the reaction from your input.

I have the standard ratio power steerig on my T/A. High speed stabiity is fine but handling is diffinately lacking.