I swapped to L92 heads/intake in my 2003 Chevy Truck. I still have one tap on passenger valve cover and one on valley cover not connected to anything yet.

I have noticed that my engine is burning oil and had some detonation under part throttle in high gear.

What would be the correct PCV setup with L92 Heads/Intake on LQ9 engine? Where should I connect those two open to atmosphere taps?

 

Valley cover you can connect to the L92 intake manifold, but it's not really needed. Just cap it if you want. The passenger valve cover vent you can tap into your intake tube pre-throttle body.

How'd you get a 427 LQ9? Sleeve? Any numbers?

 

The L92 intake has only one tap and it is connected to back of driver side valve cover. The valley cover tap is capped now. There is no tap on L92 intake or Throttle body to connect the pass valve cover tap to it!. I guess I have to weld a tap to the CAI tube.

Where does the valley cover tap normally connect on LQ9?

I got 427ci using 4.125" crank stroke and 4.060" bore. It made 450rwhp/460rwtq but it was with 1 3/4 headers and restrictive flowmaster muffler. I think the L92 intake is also limiting it and my camshaft is small.

 

you need about .080 at least is what my engine builder told me.. Are the seals in good condition?

 

The passenger valve cover connects to the intake tube on the L92 or maybe TB like a normal LM7. The valley cover line normally connects to the intake manifold just above the connection, at least the LS3 does I believe.

That's a serious stroke crank right there.