Author Topic: How did Chevy Use the same block for a 350 as a 302 in 1967?  (Read 3640 times)

Hot Rod Todd

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How did Chevy Use the same block for a 350 as a 302 in 1967?
« on: January 25, 2009, 03:13:36 PM »
Ok, This has been bugging me for a long time and I have to start this post. Let me explain what I have in my books. Ok we know this:

The 350 was first introduced in 1967 in the Camaro. The engine block casting was 3892657 and according to my book was 1967 only and was used on 302, 327, and 350.

In 1967 the Z/28 302 was a one year only small journal crankshaft and very rare.

In 1968 they changed the Z/28 302 to the large journal crankshaft and used a different engine block as well, casting 3914678.

In 1967 the 350 was introduced and the crankshaft was a large journal. This again was a one year crankshaft and all were forged steel. Also, noted that this was the only large journal crankshaft offered in 1967.

So, how did they put this large journal crankshaft in the very same block casting number that is a small journal block? Did they just machine the block and main caps to accomodate the large journal crankshaft?

william

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Re: How did Chevy Use the same block for a 350 as a 302 in 1967?
« Reply #1 on: January 25, 2009, 05:31:50 PM »
Yes; that is really all there was to it. They may have had a dedicated station set up in '67 for machining 350s.

Rich1691

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Re: How did Chevy Use the same block for a 350 as a 302 in 1967?
« Reply #2 on: March 18, 2009, 06:09:41 PM »
  Is the 1967 350 rod a different casting or a small jor. rod bored out. ? I know the rod bolts are 11/32 instead of 3/8.

69Z28-RS

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Re: How did Chevy Use the same block for a 350 as a 302 in 1967?
« Reply #3 on: March 18, 2009, 09:04:47 PM »
I think the poster was questioning the 'small journal' '67 302 crankshaft (essentially a 283 crankshaft)...  and the reference to use in a 'large journal' 350 '67 block.

I've always thought of the '67 302 as being a '327 block' and '283 crank'....   '67 327 blocks were 'small journal'.. It would seem one of these possibilities are true:

1)  If '67 350 engines were large journal, then the difference between the 327/302/350 blocks that year is just a machining issue when they machine the main journals?   OR
2)  '67 350 engine blocks were 'small journal' as cast...  OR
3)  Otherwise, it would appear that '67 327 and 350 blocks are not the same.
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

KurtS

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Re: How did Chevy Use the same block for a 350 as a 302 in 1967?
« Reply #4 on: March 18, 2009, 11:44:09 PM »
1 & 3.
They just took the same casting and machined it for the larger crank and clearance for the crank throws.
After you machine them differently, obviously they aren't the same. :)

Kurt S
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MyRed67

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Re: How did Chevy Use the same block for a 350 as a 302 in 1967?
« Reply #5 on: April 18, 2009, 02:45:10 AM »
  I have done a lot of research on this subject, as I would like to make my Camaro a Z/28 tribute car.(I have no intention of ever passing it off as an original Z, as I plan to leave it an Auto. car probably 700R4)   My 327  2bbl. block casting code is the same code that they used for the Z/28  302 engine block.   The suffix code will tell you what application it was used in.(mine is ME)(Z/28 302 was MO I believe)   Your idea that the 302 is a 327 block with a 283 crank is correct, both 283 & 327 were small journal for '67, so the 283 crank would swap right into the 327 block.  I believe that the 350 was large journal from the get go, so the 283 crank will not swap in.   Hope this helps!
1967 Camaro  LOS  11A
Original Engine   Z - Tribute
Mike C.    NW - Illinois