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72 402 Block With 3999289 Casting # ?????

75K views 8 replies 6 participants last post by  supersport6667 
#1 ·
Just bought a 1972 454 block, casting # 3999289. The guy told me it was a 402 and gave me the casting # 3999289 (72-75 454), not the 1972 402 casting # 3999290. I got there looked at the casting# 3999289, then the date JUNE-72, then looked at bottom side it was cleared for 4" 454 crank, looked at the deck and it was stamped CTB 402 240HP, I then miced the block, the guy said he just bored it .030 over and the bore was 4.155 a .030 over 402 bore. Has anyone ever seen a 454 block with a 402 4.125 bore?????
 
#5 ·
Bore it another tenth and make it a 454!
 
#6 ·
The block is a 454 block according to the casting number, but it left tonawanda as a 1972 402 or it wouldnt have been stamped with the CTB code and the block has a vin # on the deck. The guy I got it from said it was STD bore (4.125) when he got it and he rough bored it to 4.150. Its just odd they used the #289 casting block for the 402 instead of the correct #290 casting block. The casting date is on pass side backside of block. If this block left the plant this way I'm sure there were others. Imagine having an original 69 396SS chevelle with a #512 block instead of a #272 block, would have a hard time trying to prove block wasnt a restamp.
 
#7 ·
This is not the first time I have run into engines with casting numbers that were built as something other than their intended purpose. Friend of mine has a 71 #512 block that is also 402 standard bore and a 402 Suffix code. Oviously a factory mistake, anomoly, whatever word you want to call it, but it did happen. Also goes back to the fact that casting numbers were really only used to identify parts before they were machined. Afterwards, they were ID'd by the production stamp or part number of the part. Casting number is now no longer used by them as a reference, since it can be machined different ways i.e.... Can be made into a 2- bolt, or 4-bolt block. Casting numbers are a great reference for us to use, but the part must always be checked to see if it was machined to that application, or used for something different.


Jeff Dotterer
Dated Components
Diamond Restored Judge
 
#9 ·
Block is a 454 block, it just wasnt bored 4.250 from factory it started life at 4.125. I am going to bore block again to 4.250 as I have some std 454 pistons been wanting to use for sometime and dont really feel the block as any collector value.........
 
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