Ive seen one for standard model A's and have heard nothing but good things about them and the company. I have no reason to doubt the AA version would be any different.
Would be neat if they made one that permanently changed the ratio. With the dual high gearbox there is your low range - the high speed ratio of 5.14 :1 for an unloaded truck is what kills the speed so a permanent overdrive would be perfect.
AA Ford Discussion Group relating to the repair and restoration of your AA Ford.