It is not a double cardan up top. It is a standard truck drive shaft, 1 u-joint up top and 1 down at the axle yoke. The length looks like it will be ok as I only ended up with 4-5" of lift. I will have to double check but the reveal on the slip joint looks like it is only about .75" out from where it was stock. I will try to take some pictures tonight when I get home from work.
Vochy: '06 F-150, Black Supercab Short box, 5.4L 4x4 XLT, 1" Daystar Leveling Kit, 275 70 R17 BFG A/T KO's
88' F-150 Black Short Box, 302 4x4, true dual flowmater 2in exaust, Mustang equal length headers, 31X10.50 R15 BFG A/T KO's, New Doors and Fenders installed, MAF conversion, Six Liter Tune up, Saginaw Power Steering Pump upgrade, P&P GT40 Heads, 3G Alt Upgrade, D44 SAS and 9" rear in-process.