Wow that looks like a whole lota work for what your getting. Go for the PCV catch can. Since ive installe mine the oil level has been about the same but I do see it go up the more I race around.

During just normal driving the PCV hasnt filled up anymore than it did. The filter im using wont allow any vapors inside so im sure its doing its job.

 

gm pcv systems suck on these vehicles because they had an old style pcv valve the wasnt calibrated right and pulled excessive vapor through, since they figured that out they have a new style pcv valve with no moving parts, its a fixed orifice and doesnt pull as much vapor through, i dunno why, i guess the old style valve spring inside was too weak and let the valve stay almost open at all times, here the write up from gm: Some customers may comment on higher than expected engine oil consumption. They may further comment on consumption in the range of 3,200 km (2,000 mi) or less per quart (0.946 liter) of oil under normal driving conditions.

Cause
The condition may be due to the positive crankcase ventilation (PCV) valve flow rate under certain engine operating conditions.

Correction
Verify that the oil consumption is not the result of an oil leak or other engine concern.
The dealer should perform an oil consumption test. The vehicle should have accumulated over 6,450 km (4,000 mi) before establishing the oil consumption rate. Reference Corporate Bulletin Number 01-06-01-011, Information on Engine Oil Consumption Guideline, for details.
Remove the PCV valve and inspect the hose going to the intake manifold for signs of excessive oil being present.
If excessive oil is present in the PCV hose, replace the PCV valve (Type 948C) (2) with a new-style fixed orifice PCV valve, GM P/N 12572717(1). See the illustration below.

 

How much is it?

 

So, do you'all think this could this mean the 04s probably have the new style?

 

I have the new style PCV Valve in my 99 5.3 and it still sucks oil. I put a mini air line water separator in line (just like I read about in a forum here), and in about 100 miles there's about 1/2 a teaspoon of oil in there. The engine only has 37K and I've changed the oil religiously with Mobil1 5w30. So far the separator works great, I'm just thinkin that I might need a bigger one if I don't feel like draining this thing once a month.

 

i have found that the new pcv valves usually works, but maybe the answer is to convert to ls6 pcv system, run the new vavle and a catch can, if its possible, i dunno where the catch can would go, maybe try just a fuel filter for the old carbed engines.
just a thought