I've got 6th edition Chevy power book, printed in 1988. I just went through it and there is no mention of the 010 or 020 blocks anywhere. When it talks about block selection, it mentions only checking for a good core based on block condition, cracks, core shift, etc. It then goes on to talk about the benefits of bowtie blocks, or aluminum blocks. The 1988 version makes no distinction between the 010 and any other blocks.