this #2 hole the others less 4 are clean

I would say the first picture, #4 hole, the insulator is so clean, it doesn’t appear to me to be burning oil.  The oil on the threads appear to me to be coming from outside the engine, like from a valve cover leak.
 
The plug from the #2 hole looks to me like that cylinder is burning oil.
 
The last picture of the plug looks like it may be running a little ‘hot’.
 
What heat range are you running, and are all the plugs the same? (sorry to ask, but need to be sure they the same)

What kind of pistons are in the engine (cast, hyper, forged, etc.)?

MS wrote:

Be sure your PCV valve is not sucking oil. If you do not have a proper valve cover baffle blocking oil must from getting to the valve, it can cause oil consumption.

I don’t see any issues with those spark plugs.

I had this problem as I had removed the baffles inside my “Cobra” valve covers as the roller rocker arms hit the baffles.  I modified the original baffles to fit and haven’t had issues again.
 

BobE wrote:

MS wrote:

Be sure your PCV valve is not sucking oil. If you do not have a proper valve cover baffle blocking oil must from getting to the valve, it can cause oil consumption.

I don’t see any issues with those spark plugs.

I had this problem as I had removed the baffles inside my “Cobra” valve covers as the roller rocker arms hit the baffles.  I modified the original baffles to fit and haven’t had issues again.
 

I did the same to my valve covers that were getting hit by my roller rockers. I pulled out the rivet/screws that held the baffles on and removed some material on the boss that the screws went into to gain some clearance.  I reinstalled the baffles and no noise. I also fabbed up a thin stainless steel baffle that I  installed under the PCV valve so that the valve wasn't sucking oil mist all the time. Needless to say, my oil consumption went way done then.
 

Last edited by Ron68 (8/10/2022 10:50 PM)

Thanks everyone. Baffles are what come in stock 289 covers. The PCV is a very tiny hole fixed orific and the oil smoke comes out of both pipes all the time, even under acceleration 
Im not sure on heat range of plugs but I think they are 46 autolites all 8

Make sure the PVC valve isn’t stuck ‘open’.  The ‘old time’ check was to shake the PVC valve and listen (and feel) it rattle.  I had a car where the PVC valve broke inside and was drawing vacuum, and oil, all the time.  This impacted the car idling (due to higher manifold vacuum) more than at higher RPMs, but maybe something to check. 
Cylinder compression check can identify the bad cylinder(s).
What type valve seals are you using, and do they only have 2600 miles on them?
What is your manifold vacuum at idle?  Could you have sealing issues with the intake manifold to cylinder head?  Leaks at this point can result in oil being sucked into the intake ports from the lifter valley.

I'd ask your engine builder/machine shop if the valve guides were replaced.  Or, if they check them....

Unfortunately for me, my machine shop reworked my GT40P heads but, only a short time later, the valve guides needed replacement.  Upon engine start, my exhaust was emitting blue smoke.
I pulled the heads and another shop replaced worn valve guides.  Now,  no issues.
Not saying this is your exact issue...just sharing my similar experience.

To clarify, my left side was emitting the blue smoke but, I had valve guides replaced on both heads...

Last edited by josh-kebob (8/11/2022 11:11 PM)

Before I "modified" the baffle in the valve cover(around the PCV)....it sucked oil pretty good and smoked on start up.

Just a thought........you didn't by chance put in a hi-volume/high pressure Oil Pump did you?
6s6

Does the exhaust have a crossover (H or X pipe)?  If so I'd expect an issue on the left side to come out the right pipe as well and vice versa.

The simplest way to make sure it isn't the rings is to do a leakdown test.  What type of ring compressor was used to install the pistons?  I now only use a tapered compressor because I found a couple broken rings in an engine that I put together with the one size fits all coffee can type compressor.

If it passes the leakdown test the rings are sound and I'd move to the top end.