One thing to watch with the vortec engine is a little known fact that at about 100 to 110 thousand miles a fuel sending sensor below the intake manafold goes. I have a Jimmy with that motor and the dang thing decided to take a crap on a major highway around here. The remove and replace of the sensor isn't bad, but the part is ONLY available at the dealer, and will run you about 500 to 600 bucks. Symptoms of the problem are hesitation and slugish starts. Almost like it needs just a tune up.
Rob :-P 8-)
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