Ok so the shocks weren't up to par anymore so I replaced all of them just this past weekend. Replaced a broken swaybar endlink (replaced them both when I was doing it) today. I still have a rattle in the front end and came to find out that both lower ball joints are on the way out and need to be replaced. Does anyone know if I need to have an alignment done after replacing all 4 of the ball joints (2 upper, 2 lower)???

Also, the hesitation that I noticed as soon as we purchased it has started to get worse. Now the symptoms have become more and more evident. I have a rattle when I give it some gas and the vehicle is at a slight angle (can you say bad catalytic converter). Well, here'* what confirms it. The hesitation is much more prominent when the truck is FULLY cooled down. By the time that I get to the stop sign at the end of my road (<1/4 mile away) it is better, but still not right. It has decent acceleration, but not like my buddies 2k Blazer (same except for the AWD). Now the dealership had told me that this hesitation was just a 'characteristic' of the AWD system and that some AWD vehicles have the hesitation worse than others so you can't compare one to another (haha - bullsh!t!). Now, I read on Autozone'* website that OEM'* warranty their cats for 8yrs or 80,000mi... Is this true? If so I should get a cat for free. I know it isn't covered under the limited 60day/3000mi warranty (NYS Lemon Law Warranty), but is it still covered by GM?

Please let me know. I'll be calling the dealership tomorrow to have a discussion. I don't have a problem replacing the ball joints. Only the bottom ones are bad, but if I have to have an alignment, it'll be cheaper in the long run to replace all 4 and then get the alignment than to just do the lowers...

Yes you will need an alignment with either 2 or 4 ball joints changed. If you scribe everything before you take it apart you will very close but will still want to have it measured to be sure.