"I have an old GE breaker panel (estiamte 70's or later). All of the newer panels I have seen have a seperate ground bar, mine does not. There is a grounding strap from the neutral bar to the box casing. Am I to assume that I can simply ground the circuits I am adding to this neutral bar?"

In panels that old the answer is yes. The Neutral and Ground conductors share the same bus bars.

On current panels the same could be said for Neutral and Ground because the Neutral conductor is bonded (electrically connected) to the metal of the cabinet.

However, bus bars are provided for separate ground conductors and neutral conductors.

If you were to create a sub panel, than Neutral and Ground must be isolated.

Just out of curiosity, Is there a ground wire pulled with each, or did they use the conduits for grounding?

Whether the panel is old or new is not the issue with having separate ground bars.

Any panel that contains the Main Breaker will have the neutral and equipment bar either use the same bar or have two bars be connected together.

Any panel that does not contain the Main Breaker must have the neutrals and equipment grounds separated.

Well TK, you just found yet another problem with my main panel.

The Neutral and Equipment grounds are joined together at the bottom of the panel.

Sorry.

Sounds like you bought a real Money Pit.

I hope you don't use what you see in your home's wiring as an example of how thngs should be done, and give advice based on that.

I keep pounding about where the neutral and equipment ground can be connected, and where not.

No, I use my panel and wiring as how it should not be!

I work very hard at giving advice on what I have learned over the years.