is this a 258 or 232?

I bought a house and this one of the thngs left behind. here are a few pics...the first numbers are 3235077 and the next pic is 306c04.

 

I "think" 1980 258. But would have to stop and look it up to be 100%.

 

Did you find out if it was a 232 or 258
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Hi a, c, =258 e = 232 so you have a258

 

That's right for the build-date number, but I doubt the casting numbers are the same as the build-date number. The 232 and 258 block are the same, so the casting numbers will be the same. Only the crankshaft and rods change between the 258 and 232.

What's the number stamped into the block, on the passenger side center?

 

Looks like a 2bbl 258 built June 4, 1979 according to: http://www.amcrc.com/tech/engine.html

Shown as a 1980 according to these casting numbers: (Don't ask me where these came from, I can't remember. I found them on the web some time ago and saved them in a Word file without a source.)

AMC 258 4.2L
Block, Crankshaft & Head Casting Numbers
____________________________________

1975-79 258 4.2L - 1/2" Head bolts

Blocks: 3227445 and 3224098
Head: 3227258
Crank: 3214723
_____________

1980 258 4.2L - 1/2" Head bolts

Block: 3235077
Head: 3227258
Crank: 3214723
_____________

1981-85 258 4.2L - 7/16" Head bolts

Block: 3235444
Heads: 3933000, 3224480, and 3241656
Crank: 3235477
_____________

1986 258 4.2L - 1/2" Head bolts

Block: 3227444
Head: 3933002
Crank: 3235477

__________________

 

Looks to me like that's referring to the stamped engine code, not the casting numbers. I would not assume that the stamped and cast numbers are exactly the same. Maybe they are... but the block will pre-date the engine build date.

I don't doubt the numbers you saved though. 3235077 is clearly an AMC part number. I don't know what the other codes mean though.

 

I don't understand what you're saying Tim. The stamped build date is not reliable? I would think it would be a more reliable source than the casting number, because as you said, 232 and 258 blocks were identical and could share casting #'s, but the build date code tells you the engine assembly date and its final configuration (2bbl, 1bbl, displacement, compression, etc) as assembled. Of course the block will pre-date the engine build date, it's impossible in the time-space continuum to assemble an engine that hasn't been cast yet

Regardless, I think it's very clear from all sources of evidence that he has a 1979/80 258, not a 232.

After further digging I found that the 3235077 block castings were only used in the 1980 MODEL year, which means the engine was assembled in 1979. I also have a 3235077 block in my CJ, which was assembled in August of 79. Far as I can tell the only difference from the <79 castings was the moving of the location of the temp sensor to the back of the head for the 80 model year.

 

Oh oh oh. Never mind. My mistake. I looked at the picture above and thought those were casting numbers. Instead they are the stamped numbers blown up large. For some reason, the looked like they were cast-in to me.