The tremec has always been a good street/economy tranny. I've always thought the gearing was never right for a high hp/low weight car, as the gear spacing was too wide, wider than a wide ratio toploader, and the spread between 1st gear and 5th was so large that it made one of these two gears, depending upon the rear end ratio, unusable. With the 4617 TKO as listed,
www.ttcautomotive.com/English/news/20news.asp ,
the ratio's are similar to a wide ratio toploader 2.78/1.93/1.36/1, but the toploader gear spreads are more even in % drop. Using a wide ratio toploader, with appropriate rear end gearing, you really don't need overdrive, so I'm not sure how valuable the .82 overdrive is even in this new tranny.
I think if Tremec made their trannny with 1st through 4th similar to, or the same as a close ratio toplolader 2.32/1.69/1.29/1, and then had the .82 overdrive, that would be the most ideal for a high hp/low weight car.