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.

 

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

 

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.

 

It's a 4.8... simple. Especially if it's all stock and not rebrew someone slapped together.

 

Thanks. Then it also has to be 2010-2013. Then are there any aluminum block 4.8s or are they always iron block?

 

4.8s are all iron.

 

Wouldn't a number be cast on the front of the motor?

 

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.

 

 

I have stumbled across a few fullsize van 5.3s that had VVT but no DOD.