He is looking at the LS1 version of the T56 Magnum. Those use a 31 spline Ford C6 yoke. No big deal, the Magnum is Viper T56 basically with the trans mount a little less further back and a few different shifter location options. But other than that it installs just like a Viper takeout. Why Tremec didnt call it a Viper/LS1 app I dont know, they must of figured it would be the lesser of 2 evils to confuse the Mopar guys instead of the Chevy boys.