I did the center swap on my HO52 to 4.10/4.11 gears with a T5 and 225/75 R16 radials and it cruises very smoothly and quietly at 58 mph on relatively flat ground. Mine has a .78 5th gear I believe.
Here in Eastern Ohio we have some steep grades and 4th gear can only hold 40-45 with a run for it. But I love the T5 and would never want to give it up.
