Johnny;
The pushrods you got with the 292 motor should work fine (I think) with the "G" heads. I would make sure they are not bent. You can roll them on a piece of glass or other flat surface to check them out. If any are even slightly bent, I would replace the set. 
It would help to know which ratio rockers you have. Look on the rocker arms for the numbers. The ECG-6564-B2 are the high ratio (1.54:1) rockers. The 1.43:1 ratio rockers have numbers like 5751066. At least those were numbers off rocker sets I've had in the past.
Rono
Ron Lane, Meridian, ID