According to John McClain of the Houston Chronicle, the Texans will implement a 3-4 defense if they hire Wade Phillips as defensive coordinator, as expected. t's a major adjustment, and one that will require the Texans to pursue a true 3-4 nose tackle. At 6'6/295, Mario Williams will probably stay at defensive end. John McClain of the Houston Chronicle notes that Bruce Smith had 65 sacks in six seasons under Phillips in Buffalo, including a high of 13.5 and never fewer than seven. The Texans' top 3-4 outside linebacker candidate would be Connor Barwin. SLB Brian Cushing would kick inside. Source: John McClain: Twitter.com
A more in-depth article.......pretty good stuff: Happy New Year, Thoughts on Texans' defense, and keep those comments coming | NFL | Chron.com - Houston Chronicle
If they go to a 3-4 then Okoye and Cody have to go. I don't think either of them would be a good a NT.