Quick rundown...
My 06 gto has been my daily driver since 08, love it, great car. Unfortunatly a few years ago I dropped a valve in my mildy modded factory ls2 (cam/fast92/kooks). I then purchased a used raw longblock (no oil pan/throttlebody/intake/the works) lq9 6.0 iron block to replace it (cam was almost identical specwise to the one I had in the ls2) and just swapped all the stuff over.
Well for the a good while now my Oil pressure has been terribly low (not the sending unit, already went through 3 of those and got a mechanical gauge just to make sure it wasnt a ls2-lq9 swap thing.) oil pressure at idle never goes above 14-15. It does go up with rpm (around 30 at 3k rpm)
Last week I replaced the oil pump with a melling and was very careful with the o-ring and that didn't help, I then took the drivers side valve cover off and started the car and THERE WASNT A DROP OF OIL GOING THROUGH so ive research and the cam retainer plate (last owner installed the current one, the farthest i had went behind the timing cover was my chain and gear from the ls2), have it tore down at this moment with the new recessed plate and bolts and pray that fixes it. But anyway, thanks for making it this far, I just wanted you guys to have all the details so somebody could help me finally fix this NEEDY redhead...

I notice the brown lines from oil dropping lower on the plate than the shape of the galley seal that goes there. idk im about to just give up on it

Edit: forgot to mention, when I got the lq9 i bought the valley cover that has the holes for the knock sensors AND has the PCV, I just drilled and tapped a hope in the block and plugged the holes. car doesnt make any weird sounds or lifter squeal and seems to run okay, which blows my mind

 

Did it always have low oil pressure after the block swap?

 

To be honest I have no clue, gtos dont have an pressure gauge and it ran/sounded fine for 2 years now. It was by happen-en-stance like a month ago that I stumbled on the torque obd2 phone app (freaking amazing app) that i figured out it was low. Since then ive been working so hard trying to figure it out that sherlock holmes would bow his head in awe.

 

If anyone can think of anything I can do or check while I have it tore down this far it would be MUCH appreciated! Seen somewhere that the barbell in the oil galley on the back of the block could also be the villian. How complicated is that to check/test in a t56 car?

 

Was it making any noises? That really isnt all that low of oil pressure.
What about the barbell in the block?

 

No it sounds fine and has ran good the entire time ive had it (almost 2 years) I wouldnt even know about it if it wasnt accidental. but Idk how. Lifters under driver side valve cover were getting 0 oil.
Theres another barbell in the block other than the one on the back drivers side?

 

Nope, just the one barbell.

 

 

Did you have a Torrington bearing on the back of your cam sprocket when you pulled it off? From the pictures I can see that the cam is wearing aginst the cam retainer plate. That is not supposed to happen.

 

Did you use the cam sprocket from the old engine, with crank sprocket from the new engine? Maybe they're not exactly aligned, which would explain the wear on the retainer plate.

 

I didnt know there was one there. There was no bearing when I pulled it off, so I just replaced the retainer plate and bolts, damn... I just got everything back together too lol

 

Yeah I did, I had to change to my Ls2 reluctor wheel, is there any obvious signs to look without having to tear back into it?

 

AFAIK, only the aftermarket cam gears had bearings, OEM does not. So don't worry about it. When you swapped blocks, did you verify main bearing clearances? I'm betting they're on the loose side and causing the low pressure. If it was a restriction or leak somewhere you would have smoked something by now. Any glitters in the engine oil?