Does anyone know if the alternator and power steering brackets and a/c mounting between a 1970 and a 1973 Block and heads are different.
My engine came bare and I'm looking for these parts.

 

I am not clear on what you are asking. But if you need 1973 parts I have the following for sale off of a 1973 engine:

- Alternator bracket
- A/C bracket
- Power steering pump and bracket
- Associated pulleys

PM me if you are interested.

d1

 

The brackets are different, but mount in the same way.

Since there were several different configurations of accessories, your best bet is always to use the brackets and pulleys that came with your car.
If not that, then use a matched set of brackets and pulleys - Don't mix and match.

- Eric