So the other day I picked up what I thought was a 250ci Inline from a 1968 Nova. I get home today to check casting #'s on the block, head, carb, etc to be sure I picked up the right mill. Well, the casting #'s on the side of the block reads 3921967. According to the inliners site , that is the casting for a 1964-69 230ci inline. Now, I dug a little deeper because I wasn't satisfied with that one result and was bound and determined that I had the 250. After further reading, I learned that starting in '68, Chevy started stamping VIN information on the block near the distributor that included the intended application for the motor. Well, underneath a good layer of grease and dirt, I uncovered F0610CM. According to Nova Resource, the intended use of this block is a 250ci that was paired with a 3 speed. My question is which stamp do I trust without tearing the block apart? I have a feeling this is the 230 block with the 250 rods and pistons, since both the 230/250 have identical bore. Was GM cutting corners and just ***embling these blocks differently while using the same casting #'s for both the 230/250? Anyone who can shed some light on this would be much appreciated. Thanks in advance.
the stamped numbers on your application is probably the right info. i had a 71' 307 out of a one owner vehicle and the casting on bellhousing said 61' 283.
find the casting date code on the side of the block, I think it's near the starter, that will tell you the year. It's a letter followed by a few numbers like F 8 7, the last digit is the last digit of the year. The suffix codes were used for different engines sometimes in different years. CM shows up as 67 250 chevelle 68 250 full size, camaro, chevelle, nova But either way it looks like it's a 250 engine.
230 and 250 blocks are identical. The only difference is the stroke and piston compression height. Look for a dish on the piston. Walla 250. Flat tops in a 230
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