With the HP out the door of the factory, the 727 had enough strength and durability. IMO, it's just common sense if you add HP up front, that you add strength all the way down the line. A 425 HP Hemi up front, a Hemi torqueflite in the middle and a 8 3/4 in the rear, you can beat it all day long and into the night with no problems. Add 200 HP up front, you damn well need to think about the rest. Transmission, rearend, suspension, and tires never need overlooked.