I just replaced the spark plugs and I went with the AC Delco plugs due to the overwhelming support from forum members. The two hard to change plugs were in very bad condition and probably had never been replaced. I noticed an increase in throttle response which was great. However, within a day or two after changing the plugs there has been an odd "hit" feeling every so often. The truck will be idleing and then its like "bam" somthing has missed. It's a very short miss and the truck keeps idleing like it never missed a beat. Although there has been an instance since replacing the plugs when driving in town that the truck had no power. I turned a corner and their was no acceleration power; floored the gas pedal to gain power; came to stop sign; took off fine across a street then loss acceleration power again; floored the gas to regain power and was home. Is this "missing" or "hitting" feeling caused from the new plugs? Will this eventually work its way out? Thanks