I just performed a complete engine rebuild on my '97 a few months ago. I used the stock pistons, rods & crank. Replaced all the rings, bearings, gaskets, timing set, etc. I also put in a CC503 and supporting valve train components. The car is running perfectly, has all the power you want and does not leak anything. I had the exhaust off about a month ago from the headers back. I decided to fire the car with open headers and let it run for just a few minutes. The exhaust is smoking blue on the left(drivers side) bank only, and I would say it's more than "warm up" or "normal". I have not done a compression test on it yet but I think that's probably the next step on my list. Here's the thing: I have a double catted Y pipe just after the headers. When the car is fully warmed up, it does not smoke at all that I can tell(when the exhaust is fully connected. I'm wondering if the heat of the cats is burning off the oil that is coming out of the left bank before it gets to the back of the car where the exhaust exits? I don't know if maybe I have a broken piston ring, broken valve spring, or maybe a valve seat that has gone bad. I have driven next to the car while it's going down the road, and accelerating from a dead stop(wife driving the Z), and I did not see any smoke whatsoever. I know it is burning oil because it's not leaking any and it's using about a quart every two weeks. Any ideas?

Could also be an intake gasket. I had a set of Felpro blue ones go bad. Apparently something changed because within a few month I had a set of those go bad and so did friends on both a gen 1 sbc and a BBC, all experienced wrenches. We think the problem might have come from coating the Felpro gaskets in silicon because the silicon bead on the gaskets delaminated and sucked into the ports. Theory is the coat of silicon we gave them caused the delaminating by reacting with the layer already on the gasket.

Intake gaskets
Rings didn't seat
PCV system
Valve guides/seals

There's quite a few things it could be...
Was the block honed with a torque pate to the proper Ra value for the rings? Heads rebuilt with new guides and quality seals?
What method did you use for sealing the intake manifold?

Intake gaskets huh? Never even thought of that. The block was honed and looked great. I gapped every ring and every single one checked out perfectly. I did not break any rings when I slid the pistons in, I did it very carefully. The heads were completely rebuilt, valves ground, new good quality felpro seals. For the intake manifold, I used fel pro gaskets with the silicone bead built into the gasket. I was told by my engine machinist to put something called "high tack" or "brush tack" on both sides of the intake gaskets to help seal them. I did that, maybe that's what's going on. I am pretty sure the pcv system is working properly. I am having a hard time understanding why intake gaskets leaking would cause the engine to smoke blue? Maybe someone here can chime in and explain it, i'm a little lost for words on this one.

In the valley under the intake, oil is circulated for the lifters etc. If the gasket is leaking, it is possible the oil can enter into the valve chamber and into the engine. However if it's leaking into the intake valve, it should show up on the plug as burnt oil.

If it were leaking into the exhaust valve area, it should simply blow it out the pipe without it ever going into the cylinder.

But, there are tests that can be done to see if such a case exists. For example, the crankcase vacuum level should go down if there was a leak. Obviously a manometer could detect it. A faulty PCV system could be detected as well with a manometer.

A compression test in your case will probably not show anything wrong. A leakdown test would be more prudent. But that will not show intake gaskets leaking. Only shows faulty rings sealing, valves and head gasket.

BTW if you're burning oil to the cats, then it(they) are shot.

Pull the plugs to see what's going on. Leakdown while you're there.

How do I check for a malfunctioning PCV system, and crankcase vacuum? I would agree with you that a compression test would probably come back just fine. As far as the cats, they don't put a sniffer onto the exhaust here, they just plug into the OBD2 port and check to see if there are any SES lights or codes thrown. No codes=pass smog. Oh, and it is not smoking all the time, off and on it seems. I just drove it and let it sit idling for about 5 minutes. It was smoking blue, but not a lot. When I got home, I let it sit there and idle for about another 3 minutes and it was not smoking blue, it did however produce a little steam or condensation from the cold air.

Your getting ahead of yourself. You need to pull plugs. You need to get rid of the cats. With the oil in them (or 1 of them) they are no good now and will likely clog.

Read up on a manometer. Remember if your using the type with water. Plug or pinch off the hose until the engine is running and then before you shut off the engine.

I'm not seeing how oil from a bad intake gasket gets to the exhaust valve. And if it did it would be burned in the chamber as well.

Another spot to look is the rocker studs. Many times the studs will enter the ports after porting. Simply sealing them with Teflon tape fixes that particular issue. This can also answer the side to side differences....

I also think the cats can tolerate a small amount of oil without failing. Excessive amounts will cause the cat to overheat and can fuse the matrix but small amounts should be OK.

Pull the plugs and give them a read and then decide what to do. Getting rid of the cats for you means tuning them out....an expense you may not need...

I am going to pull the plugs the first chance I get. I'm sure one out of the four plugs on the left bank will have some oil on it. What's really weird is that it is not burning oil all the time, or if it is, it's not enough to notice. Maybe it's a bad valve seal, but they were all brand new a few months ago. If the cats are clogged which they aren't yet, I can just remove them or replace them, not too worried about it right now.

Oh, and the heads are bone stock, no porting.

Well if you know the plugs are going to have oil on them, then oil must be present in the cylinder. So you should just go ahead and pull the intake if you are so sure. At that point it will be obvious if you stop with intake gaskets or have to go further to the head.

Cat's can't take ANY oil what so ever before they become useless. The change to the substrate's surface then makes them a soot (spelling) magnet.

He does NOT need to have the cats programed out. Even if his programming still recognizes their presence, he could simply put simulators in place. Like the ones I bought for 30 dollars over 6 years ago and still use today.

How many people have actually had this same problem i'm talking about, and it actually ended up being intake gaskets? I don't want to yank the intake if there's nothing wrong. There could be a chance I have the PCV hooked up wrong, maybe have a bad PCV valve or something simple like that. The PCV on my engine is on the intake manifold, drivers side about middle of the intake. The valve is right there, then to a piece of rubber hose, to a piece of solid 3/8 tubing, back to rubber hose, to the front/lower intake manifold. I had a problem before with an oil leak due to one of those hoses getting pinched off, but I fixed that and the leak went away. There is still an open nipple on the front of the intake, I have no clue what it is supposed to go to, when I got the car it didn't have anything hooked up to it. There are so many vacuum lines and solenoids/electric bs on this car it could almost be anything. But if a PCV system was not functioning correctly, would it only smoke out of the left bank? I'm almost thinking whatever I put on the intake gaskets has damaged them in some way, and sucking oil straight into the intake valves to be burned, but only on the one side. I would say the chances of me having a bad ring/rings or a valve seal going bad are very very slim.

I second valve seals, this would cause a warm up smoke as when the car sits the oil seeps into the cylinder. Then you start her up and smoke out the oil.
I don't think it could be a bad pcv, you probably would blow out valve cover gaskets if it was building up enuff pressure to seep past seals. Plus if you are sucking more oil into your intake you would see it on both banks as the manifold does not separate the runners.

Where does one get simulators today since Caspers Electronics got mailed and isn't doing it anymore??

build them your self, cost about 5 bucks at radio shack. I guess you can google DIY MIL eliminator for specs as I cannot from work. Or you can Ohm out the wires on your O2 sensor and buy the proper cap/resistor inline with your current setup.