I did that swap back in the late 80's and really didn't like it. The factory T/A AAR power steering boxes that used the longer arms for a quicker ratio also had internal stops in the box to limit the travel. The box would only turn enough to match full lock with the quicker linkage and then stop cold.

With a regular box it just keeps trying to steer even when the ball joint/knuckle hits its stop. There is a lot of assist in the power box and it would just continue to steer by flexing the chassis when the steering ran against the linkage stops.

The box would flex the chassis so easily you could barely feel when the knuckles reached full travel and the chassis just began to flex until all of the existing travel in a stock steering box is deployed. To me it just didn't feel correct.

The factory power ratio really isn't too slow; to me it seems about perfect. I think Firm Feel can build you a box with the internal stops to match the reduced arc required with the longer steering arm. As mentioned, the longer arms will often interfere with the exhaust.
-dulcich