I believe the R302 replaced fords A4 block and has since been replaced itself by the new Ford "Boss" block. Comparable to the Dart sportsman block, it is capable of handling over 1000hp. The D.S.S. blocks are stock blocks that they run through a CNC program and general concensus among most machine shops and engine builders is that they are only marginally better than a stock 302 block if any at all.

Hope that helps and I didn't post to much bogus information.