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Mystery Gen 4 Engine

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Old 10-08-2018, 11:54 PM
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Default Mystery Gen 4 Engine

A shop asked me to disable DOD on a customers 12 GMC originally with a 5.3L, VVT, and DOD. Their customer brought in a used engine for them to install in the truck. Their customer knew next to nothing about what he had and said the engine was given to him. It was definitely a 58X Gen IV, cast iron block, 243 heads, VVT, but no DOD. Standard non DOD valley cover looked like it had never been off so they don't think there was ever a DOD delete done on this. Any idea what this might have come out of? I'm thinking it might be a 6.0L with VVT but no DOD.
Old 10-09-2018, 01:48 AM
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all the Iron Gen IV 6.0's have square port heads....unless the heads have been swapped its a 4.8/5.3....if the engine hasn't been installed yet it will say on the front and back of the block if its a 6.0 or 4.8/5.3...also there is a part number on the block on the rear of the engine just below the passenger side head...if its a 6.0 it will be 12576181
Old 10-09-2018, 10:41 AM
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It was already installed when I went to the shop.They were pretty sure the long block had never been apart. It's the VVT but no DOD that has me puzzled.
Old 10-09-2018, 12:25 PM
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It's a 4.8... simple. Especially if it's all stock and not rebrew someone slapped together.
Old 10-09-2018, 12:42 PM
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Thanks. Then it also has to be 2010-2013. Then are there any aluminum block 4.8s or are they always iron block?
Old 10-09-2018, 12:52 PM
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4.8s are all iron.
Old 10-09-2018, 05:49 PM
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Wouldn't a number be cast on the front of the motor?
Old 10-09-2018, 09:30 PM
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There was no attempt to identify the engine until after it was installed. I was not called until after it was installed. Hence no one looked for any identifying numbers.
Old 10-10-2018, 01:23 AM
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Most definitely a 10-13 L20 4.8L

Im playing with an LY2 myself
Old 10-10-2018, 10:56 AM
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Originally Posted by 2xLS1
It was already installed when I went to the shop.They were pretty sure the long block had never been apart. It's the VVT but no DOD that has me puzzled.
I have stumbled across a few fullsize van 5.3s that had VVT but no DOD.


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