so im sure the question of if it can be done gets asked a lot but im wodering if there is anyone out there that has actually converted from a 2wd to a 4wd or even awd. heres why i ask, i am going to go look at an 03 silverado 2500 HD 2wd tomorrow. its got a crap ton of miles on it but hes only asking $3500. in my area you really only need all 4 tires pulling about 5 times a year but it would be nice to have the option to do a conversion down the road. if not i still think its a good deal for the money. what do you guys think?