I was unaware of the Tin/Nickel myth. I found out about the 010 block because of the problems Chevy was having with its new blocks. If anybody knows about what i type next, please let me know where it happened. During the 80s Chevrolet dealers here in SoCal were taking it in the shorts by warranty work from overheated engines. The story goes that Chevy had factories that make the blocks in Mexico, and they were not using enuf metal. They were called thin wall blocks and I had 2 454 blocks with pin holes in the water jackets and 4 454 short blocks that overheated. I also had the same amount of 350 motors and blocks. The dealership practice was if the block was salvable from a pin hole leak, a die grinder with an ice cream cone shaped stone would clean up the hole and pack it with epoxy. Normally the dealer is supposed to ship the engines out to the warranty people (If Memory serve me right) but there were pallets full of short blocks and the best ones were taken home. I do remember everybody in the know wanted the 010 350 block because of those thin wall blocks. I was told that in the 50s racers wanted the motor that Cad made for the U.S. WWll Sherman Tank. That motor had chrome sleeves. Has anyone ever heard of this?You’re thinking of the “coveted” 010 020 block, denoted by the 010 & 020 under the timing cover and rear of the block.
Urban legend has it that they had a higher nickle content which has been debunked repeatedly. To the best of my knowledge the 010 & 020 signify which cores were used in the casting process and this set were less prone to core shift therefore yielding more consistent wall thickness’s.
I have a 4 bolt 010/020 block and a 2 bolt 010 block.
I don’t see a perceptible difference between them.