I have a 2001 F-150 Lariat, and I was wondering if there are any solid axle conversion kits for it.
Any help would be appreciated.  

Have you thought about just adding lockers? How rough are you gonna get?  

I think I'm just gonna sell it now. I have a jeep xj to, and they are way easier to turn into a good offroader, than an IFS F150. But to answer your question...Pretty rough, but I don't really like rocks, I prefer the mud.
Adding lockers to a stock IFS will put a lot of stress on the front CV shafts, and most of the time the stock ones snap like crazy.
I'm not gonna sell my truck yet though, because I'm fixing up my xj. I'm just using my truck as a daily driver right now, so I don't screw it up.  

Keep your truck. If you decide to get to crazy, at least you won't be walking. I'm getting tired of giving my friend a ride everywhere.  

I won't get too crazy, but if I do,I could just get a nice small truck to drive around town in. Like a Ranger or somethin'.