Made ~600 on the dyno today, turned it up to 15 lbs. Made several pulls... by the end a/f looked great. No KR was logged with 16* of timing. On the last pull my crossover pipe broke, so after getting that fixed I headed home. The the truck was extremely fun to drive, like a brand new vehicle. About 10 miles from home I gave it a hit on a backroad and boom. Was running on a couple cylinders. I still had oil pressure so I kept driving home. Oil pressure went to 0 when I pulled into the yard.

Oil was everywhere.... I didn't see any holes in the block. And I was still able to make boost after it went boom. I also had no water by the time I got back. So my thinking is, blown head gaskets and missing the tops of some pistons?

Now what motor do I put back in it?

 

That sucks. I'd go with a 5.3 or larger though for more out of boost oomph in that tahoe. What kit are you using?

 

Go back with 4.8 or get 5.3...

 

 

So what broke? Also what fuel are you using? 15psi was maxxing that 70mm out no doubt

 

Boost held steady all day. I just got home an hour ago, I'll start tearing apart later. Premium pump gas + a hefty dose of boost juice.

 

Damn that sucks to see. In to see what went wrong.

 

No bueno. I'd like to know as well because I'm about to crank my boost up.

 

Sorry to hear that, you were making some awesome power with that 4.8. I'd go 5.3 with a bigger turbo.

 

Sorry to hear that. 95% of the time I hear about a engine failure pump gas is involved. Sounds like it blew head gasket and coolant went into the oil. Cam is prob ok still. I would prob go with a 5.3L and lower the psi.