[bergy]

This is really confusing. ZL1 blocks were machined on a dedicated CNC machine located up by the offices at the Tonawanda Motor Plant. I watched it machine the blocks. It had to be isolated so that the machining chips didn't get mixed in with the iron chips from the other production machines. All of the iron chips went over to the briquetting plant at the foundry for re-melting. Aluminum (even in trace amounts) is very bad for iron. This discussion must be referencing the later Yenko aluminum blocks.