I have been driving my 63 on the road since 2006 with a 9.5 Dynamic converter that flashes about 4200. I drive the highway all the time along with the back roads. I drove it to Carlise going up 83 at 60 mph all the way taching about 3300. Its about 90 miles one way. I have not had any problems in my 63 or my boys Dart that has been on the road since 1997 and also has a 9.5 Dynamic unit.
See here I am at Carlisle. Ron