Aluminum slant block?

2463430-20 is stamped onto the block. My neighbor has this block sitting in his garage said he will sell it to me for 40 bucks. I believe it is RG SERIES 1960-67 which makes it an aluminum block right?
Comes with just the block and crankshaft. An aluminum block sounds interesting and possibly rare?
Is the rust damage shown in the photo beyond salvageable? Screenshot_20210206-051704~2.png Screenshot_20210206-052612~2.png

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