It could take a whole book (and then some) to really answer this question.

In order to stay on topic, we'll need the original poster to clarify his question a little.

What do you mean by "Early"?
70 vs 71-74?
cars built in the fall of 1969 vs later cars?
Pre-Production cars vs Production cars?
How early is early?

Next Question, Are we discussing all E bodies, or are we limiting the conversation by make (Dodge Challenger, Plymouth Barracuda), or by model (Challenger, Challenger SE, Challenger RT, Challenger RT/SE, Challenger TA, Challenger 340 (A66 package), Challenger Deputy, Challenger Western Sport Special, Challenger Rallye, Various Challenger Convertible models, Barracuda, Gran Coupe, 'Cuda, AAR 'Cuda, Barracuda Coupe, Various Barracuda Convertible models)

Answering these two questions will help us to give you the information you're looking for.

Tav