Agree with Cab

As to your other question, No, all the (SB) heads are Not the same. (Click on Link below for Hot Rod Mag article on SB Heads)

http://www.hotrod.com/how-to/engine/mopp-0607-mopar-cylinder-head/

I am fairly new to Mopar SB's too. Just bought my first one, an LA 360, in the '74 Dodge Power Wagon I bought last November.