I have a 1990 Suburban 4x4 with a 5.7L engine and I just put a new pcv breather tube into it and drove it around for a couple of days with no problems, was coming home from work one night and all of a sudden the engine would start shaking when accelerating from a light but once I got going it stopped, it also use to make a ticking noise like a chain on a mountain bike which it doesnt make anymore. Im wondering if putting this new part in caused all of this.
If you have a vacuum leak it will cause the engine to stumble when you give it gas because it'll create a lean condition. A PCV valve that is stuck closed will cause you issues, but ticking noises isn't one of them.
Double check the "Elbow" you installed to make sure it's seated correctly and didn't crack during installation. Remove the PCV valve and shake it. You should hear the valve inside shaking freely. If not, replace it. As for you ticking noise, this could be worn lifters, valve guides or timing chain. There's no way to tell for sure without checking the engine. But with so many miles, it's probably showing its age. Nothing last forever. Just keep changing the oil and keep it tuned up.