2 Bolt or 4 Bolt Main
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Burning Brakes
Joined: Oct 2006
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From: Native Californian CALIFORNIA
Army
2 Bolt or 4 Bolt Main
Ok I am confused. I am getting confliciting information whether a 69 350 corvette block was a two or four bolt main.
Please chime in.
Please chime in.
Pro
Joined: Jul 2005
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From: ElP TX
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3932386 - 350/300 or 350/350 - 4 bolt
3956618 - 350/300 or 350/350 - 4 bolt
3970010 - 350/300 or 350/350 - 4 bolt
all 3 blocks also came in 2 bolt ... just not for the Corvette.
From 'Corvette by the Numbers, 1955-82, Alan Colvin'
3956618 - 350/300 or 350/350 - 4 bolt
3970010 - 350/300 or 350/350 - 4 bolt
all 3 blocks also came in 2 bolt ... just not for the Corvette.
From 'Corvette by the Numbers, 1955-82, Alan Colvin'
Thread Starter
Burning Brakes
Joined: Oct 2006
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From: Native Californian CALIFORNIA
Army
With these block numbers a 2 and 4 bolt main were available. From an external view there is no way of knowing is there? You basicaaly need to remove the pan and inspect?
Le Mans Master
Joined: Mar 2004
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From: Little Rock AR
To be more specific, the 3 casting numbers that were used during the '69 model year were dependant as to when your engine was built. Any of the castings could be built as 4 bolt main or 2 bolt main as the application required it to be. The base engines were machined for 2 bolt mains while the 4 bolt mains were used on the higher HP engines.
You might check the top center bolt hole on the back of the block at 12:00 (bellhousing mounting surface). Look for threads in the boss. Legend has it that if the hole is tapped, you could have a 4 bolt main block but I do not have anything to back that up. Take it for what it cost you.
-Mark.
You might check the top center bolt hole on the back of the block at 12:00 (bellhousing mounting surface). Look for threads in the boss. Legend has it that if the hole is tapped, you could have a 4 bolt main block but I do not have anything to back that up. Take it for what it cost you.
-Mark.
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do you have a specific block in mind??
Thread Starter
Burning Brakes
Joined: Oct 2006
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From: Native Californian CALIFORNIA
Army
Reason I ask is that people have commented that they have truck engines in their vettes now that are better to build up rather than a corvette enigine which is a 2 bolt main. What I am seeing here is all corvette engines were 4 bolt mains regardless of the hp.
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Again, if you know the suffix, you can tell if it originally was a 2 or 4 bolt.
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4 bolt
HZ 1969 350/300 Corvette L-48
T-H 400 4-Brl Hyd Cam, ZQ-3
http://www.chevymania.com/partsid/su...fm?block=Small
HZ 1969 350/300 Corvette L-48
T-H 400 4-Brl Hyd Cam, ZQ-3
http://www.chevymania.com/partsid/su...fm?block=Small
Last edited by FrankVincent; Feb 12, 2007 at 12:45 PM.
