What did you do to your NBS GMT800 Tahoe/Yukon Today?

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Dantheman1540

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What're you doing to it? What's the plan?

Pull out to tear down and identify the point of failure. Which I honestly have no idea what happened Long WOT pull from 2nd through 3rd gear and just a bit into 4th at about 90mph or so and it completely nosed over. I didn't hear a pop or anything but it was just holding a rough idle of about 150-250rpm and low oil pressure around 5psi. However I think that's all the pressure it should have at 200rpm. Tried to start it once and It sounded like something was grinding. Pulled it home and checked plugs, they looked good so I bored scoped the cylinders which also looked good. Drained oil and it looked good, cut open the filter and it looked good. So I have no freaking idea. I need to pull the blower and valve covers and see if anything obvious is wrong before I pull it.

My assumption is cam bearing spun and block is likely trashed as that is what happened to this block originally. If that's the case then I will likely build a forged 408.
 

Tonyrodz

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Pull out to tear down and identify the point of failure. Which I honestly have no idea what happened Long WOT pull from 2nd through 3rd gear and just a bit into 4th at about 90mph or so and it completely nosed over. I didn't hear a pop or anything but it was just holding a rough idle of about 150-250rpm and low oil pressure around 5psi. However I think that's all the pressure it should have at 200rpm. Tried to start it once and It sounded like something was grinding. Pulled it home and checked plugs, they looked good so I bored scoped the cylinders which also looked good. Drained oil and it looked good, cut open the filter and it looked good. So I have no freaking idea. I need to pull the blower and valve covers and see if anything obvious is wrong before I pull it.

My assumption is cam bearing spun and block is likely trashed as that is what happened to this block originally. If that's the case then I will likely build a forged 408.
I had a solid 70psi of Oil pressure throughout the pull before it nosed over and was only running about 8-9psi of boost. AFR also looked good.
That def doesn't sound good. I'm wondering what my guy is gonna find when he pulls out my old cam.
 

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