Was wasting time seeing what junk ebay holds today and ran across the block linked below. It's the GM Bowtie block 10051183 that sells for $2065 (retail $2489) from GM factory wholesale direct. Skip White has three new in the crate left in stock for $950 apiece. They say it can go out to 4.155". No experience with either the block or the seller so take it for what it's worth.