I have them on my truck. I have 35" tires with a 4" lift so the length would be different. You also need an adapter to convert the top post style shock to a hrizontal bolt style, since the 5150s dont come in a post top. That will also affect the length you need. See JK Adapters for the conversion piece.

Good luck

96 T100 4x4 - 35's, 4" SL, 2" BL, 4.88s, ARBs, custom bumper & E9000 winch, etc.
99 F-350 4x4 superduty supercab turbodiesel longbed