welcome to the wire! My rebuilt 2.6 had some dieseling issues and it was due to a failing carb. anything over 1000rpm would cause it to diesel when shutting down and idle under 850 would cause it to not idle. I switched to the weber carb (choke currently not working) and it will idle cold at 500rpm and about 6-700 warm with no issues. Keep an eye on the rpm when it does and doesn't do it. another cause could be timing too far advanced.
For the T-Bars, my initial crank of 1.75in required no alignment (from a driveability view). I then put the gen2 uca's on and cranked up to 2in and I had lots of positive camber. Most people put the gen2's on to compensate for negative camber and the longer arm works great. Not sure why my setup was different, but there were a few that experienced the same as me.
btw, rxinhed's comment is also very likely. I like using the Seafoam additive to clean that out along with some good gas. My old autoshop teacher used to say that putting a little water down the carb when running will clean it up, but hydrolock scares the crap out of me <img src="/forums/images/graemlins/baby.gif" alt="" />