i have a 2wd 88 4.0L comanche with an auto how could i put it 4wd i would like the 241 can anyone help me  

I would suspect you would need the entire front axle out of a 4wd Comanche or Cherokee, the driveshafts (front and rear), transfercase, and possibly transmition (if yours does not have a removable tail housing). As far as I know this is all you need, but I have never done it myself so there may be more too it. Hopefully somebody else here can chime in with their thoughts.

You best bet would be to get a totaled donar Cherokee from a junk yard, I have seen tons of them with perfectly good drivetrains just sitting in the yard. This way you know you  have everything you will need.

Good luck with the swap! Be sure to let us know how it goes!