Chevrolet Repair: 89 Suburban 350 engine, tranny, suspension, throttle position sensor, throttle body injection

Question
First off, I just got this suburban, 350 Throttle body injection, and it just had a new tranny put in it for me to drive it across the country.  Engine has about 40,000 on it.  The vehicle had been sitting for like 2 years or so, I put heat and sea foam and gumout in it.  Have drove it about 1400 miles since I put that all in the tank.  Since then, I had a very bad hesitation when first taking off, but unhooked vacuum line to EGR sensor(didn't work just unhooking the valve).  But I never tried plugging the valve off either and currently have nothing plugged off, just have line pulled off of the sensor, well it takes off much better now and doesn't bog down now. I also replaced the throttle position sensor. It still hesitates a little though, or more so, lack of power when taking off.  Looking at the fuel injectors, everyone says you should see a cone shaped mist?  I only see the fuel running around in the carb barrels at an idle and a little reved up.  I don't know how to check the fuel pressure or how to depressurize it to change the fuel filter. What about the map sensor?  Also, it kicks out of OD very easily, well kicks down one gear very easily when driving at any speed.  It just seems like you should be able to accelerate more without it kicking down all the time.  It does get almost 15 mpg on the highway, avg speed of 65, and that was with the EGR still hooked up, and with it kicking down on about every hill no matter what grade, even on the flats just trying to speed up just a little bit.  Also above 55mph or so, if you change lanes kind of quick like, and counter steer, the vehicle rocks back and forth really badly.  like the back end is swaying a lot and the front suspension is soft.  I think the front end has been lifted maybe a couple inches or so from the looks of it.  I want to put a lift kit on it to raise the whole truck up about 4 - 6 inches cause I don't like the rear wheels sitting in narrower than the front tires.  I am pretty sure the front ball joints are bad, but I think thats all that is bad on it.  My parking brake pedal will pop back up most of the time when you push it to the floor.  Any help would be great.

Answer
Hi Scott. lots of questions...if egr isn't working i would replace it. fuel inj should have a nice cone shape to them when engine running, if not then they are plugged and need to be either cleaned or replaced, to check fuel pressure there should be a port on the fuel rail that you can hook up pressure gauge, and relieve the pressure. your trans kicking out of OD could be a TV cable adjustment needed. with engine off push the button in the cable that comes from the trans to the throttle body and open the throttle all the way. you should see the cable move. that will set the shift point for the trans. body roll could be caused by weak sway bar or if body height has been changed and they never extended the sway bar links. parking brake could be the ratchet on the pedal not engaging properly, check that when you pull on the release it returns all the way...hope all this helps...merry Christmas