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What block do I have?

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1.4K views 6 replies 6 participants last post by  LeoP  
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#1 ·
I dropped my block off at the machine shop and got a call back. The block casting number is 3999290 which I thought was a 1972 402. The machine shop is telling me the bore size is 4.250" and that the block is either a 427 or 454. Is this possible?
 
Discussion starter · #4 ·
I checked the code stamped on the deck. It is CE259603. I'm not sure what that code means. It's looking more and more like someone bored the 402 block out to a 427/454. Didn't think that was possible. I'm in the process of having it sonic tested now.
 
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