This is for everyone that has a 4.2 with the stock carb or even aftermarket carb. About 3 years ago I purchased this kit
http://www.quadratec.com/products/17002_20D.htm
I am in So Cal and face probably the harshest smog restrictions in the country. With this kit I was able to dump 95% of my under hood smog equipment, I ended up with a slight horsepower increase and tremendous throttle response. I no longer stall or start rough, NO flooding, and our trips to our local mountains over 10,000' I have no more thin fuel mixture problems.
I know the kit looks expensive, but, trust me you will never look back. Any questions feel free to ask.