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Discussion Starter · #1 ·
So my motor is coming apart and Warp mentioned my block may not be a 350 at and could be a 327 (I wont mention his reasoning as to not bias the pool)... 10 internet cool points to who ever confirms WTF this is... :)

Heads are world heads. I just want to know what the short block is..

Casting numbers

18GM
3956618










 

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Discussion Starter · #3 ·
Years Casting CID Low Power High Power Main Caps Comments
1969 3956618 302 290 290 4 Z28
1969 3956618 327 235 235 2 fullsize
1969 3956618 350 250 350 2/4 cars

And i have all that info.. so which one is it? 327 or 350?
 

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Wow. Haven't seen rubber/cork intake-valley front/rear gaskets in a LONG time.
 

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if i remember right there a few ways to know if its a 327. the earlier ones were easier to tell the differences. I believe that all 327 cranks were never drilled for a damper bolt, they have pressed on harmonic dampers. I do remember when i had mine that i drilled it, so if it has a bolt, it doesn't mean its not a 327 crank. the other thing that i remember is that the mounting flange for the flex plate is different. the 327 cranks have really rounded edges where a 350 crank tends to have squarer edges on the mounting area for the flexplate. From what i know there is almost no way to tell, by the block (on the later ones, but could be wrong) or anything other than the crank and pistons. should have a different compression height to compensate for the stroke. (again, i'm going off memory here)

AP
 

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Discussion Starter · #7 ·
With the pistons that it has it's a 350. (L2256F is a 350 piston)

Yes it does. I was just curious as to what this block started life as... and if im reading this right they are pretty similar so i probably wont be able to tell...
 

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GM went away front the fully enclosed distributor "thingy" right around that era that the 350 came out. If I remember correctly only the 1968 327 had large main journals (but don't quote me on that). The last 327 I built was a 68 large journal that did "NOT" cave the enclosed distributor. On a side note, did the big journal 327's come with four bolt mains? The one I did was a two bolt out of a Vette.

Paul
 

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GM went away front the fully enclosed distributor "thingy" right around that era that the 350 came out. If I remember correctly only the 1968 327 had large main journals (but don't quote me on that). The last 327 I built was a 68 large journal that did "NOT" cave the enclosed distributor. On a side note, did the big journal 327's come with four bolt mains? The one I did was a two bolt out of a Vette.

Paul
There are some 4 bolts out there but not many.
 

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I've had ALOT of 327s and none have been 4 bolts. I don't know if there were ever any from the factory, but that can be changed easily enough - these days.

Same with the crank bolt. The 327 in my '56 BelAir - I had drilled just to help keep the FluidDamper on. It was about to leave the engine builder and I reminded him I wanted a crank bolt. His guy ran over with a drill and tap and knocked it out right there. Took 5 minutes.

So, don't always trust the non-crank-bolt-being-a-327 thing.
 

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What the Hell is That?
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I have a 327 block I believe mine was converted to a 4 bolt Studded though.
 

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GM's first gen 350 used a 327 block, there was no identifying traits as to which were which.

There are four bolt 327's. Rare but they exist.

If I was to bet, I would say an early 350..

GT :)hand
 
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