The self rebuilt Q-jet on my 489 bbc is not working as well as I had hoped. Off road it works great, but between 2100-2500 rpm on the highway, it just sort of cuts out. If I back off the gas, it will eventually cut back in. I also cannot get any change in the way the engine runs when I screw in/out the idle mixture screws, the engine just doesn't respond to those adjustments. I believe it is a carburetor problem, not ignition. Anyway, I've been thinking about a new carburetor, and I've been thinking about the JET performance products Stage 2 Q-Jet, p/n JET-35002, offered by Summit Racing. Does anyone run one of these carbs or have experience with it? Would it be worth buying one? A friend of mine runs a Holley truck avenger carb on his Blazer, and he loves it, but I'm not sure that's what I want. Thanks for any input!