If the T56 magnum is around $3000 what in the world are they doing to it to make the price $10,000 using some parts out of unobtanium?

http://www.ddperformance.com/magnum.html

How much longer is the T56 vs an 833 and how much does that change the driveshaft angle that some people mention is not a good thing when adding either a gear vendors on the tail of a 727 or installing a Tremec 5 or 6 speed trans?