we ran a 448 in our Duster.. we had main bearing failure which led to a snapped rod..when I tore down the engine,cap walk was very evident.This engine was an easy rever to 7800 but was never shifted higher than 6800...our new engine is a 499 which is now making in excess of 800+hp..we have as you know your stud girdle and I have found it very smooth..of course my wife races the car so trying to pull data out of her is...you know...we only made 3 runs since the season ended clocking an amazing 9.23 shutting down at 1000' and soft launch...Becky's remarks were"It's so smooth and POWERFUL"(a woman's insight to just about everything)..she has all the confidence in the world with this new engine...on the dyno it was smooth past 7500...when we teardown next season..we will see how well a 2 bolt main and stud girdle will do on bearings.....