Sounds like you decribed my son. My 3 1/2 son was the same way up until 3 days ago. He finally went poopy in the potty for the first time and does it all the time now. It was like a switch turned on in him and he was ready to do it. I had tried training him since he was 2 1/2, I never pressured him but I tried every method, reward, etc out there to encourage him to go at least once. Nothing worked. So I finally gave up and gave him the choice to either poop in his diaper (not in his underwear) or poop in the potty. He always choose a diaper until 3 days ago, he said "no diaper, I want the potty". I thought I was hearing things and I really didn't think he was going to do it, and 2 seconds later, he stood up and said he went poop! Just like that, I was the happiest mom on the block :)
So when they are ready, it shouldn't be any work at all - just give them the opportunity to go. I also think that once they conquire the no peeing in the pants, the poopy will eventually follow. I had my son in underwear during the day, and hestayed dry for a good week or so (no accidents) before he wanted to do poopy in the potty. The only change that I made right before he wanted to go poopy in the potty was leaving him in his underwear whenever we went out to places - I usually put him in pull-ups (since we've had our share of accidents out of the house) - but I've found that with the pull-ups, he knew he could pee in the pull-ups. When he wear the underwear or training pants, he'd stay dry. I think it took a good month or so to conquire peeing in the potty - he would always refuse to go but I backed off and let him pee on himself and with time, he learned to either hold his pee or go to the potty.
Sooner or later, it will happen. I was in the same boat for a long time and never did I think the day would come that he would be asking to poop in the potty. :) I still have to encourage him to pee in the potty, otherwise he'll hold it in, but everything is falling into place. Good luck!!