From the log You've posted I've seen both O2 sensors pulsing . Also, the fuel trims were around 5%. Can You confirm? I am asking, cause if You'd be getting:
- extra air, it will be compensated by adding extra fuel
- extra fuel from leaking the spider, the IAC would give You more air
In either case Your fuel trims would go far beyond zero. That's why I am asking.

Did You find any differences in comparison to the data posted by Les?

As for the gaskets, if You order the Fel-Pro set, You'll receive them all together, for lower and upper intake.

 

8

1

2

6

10

3

9

4

5

7
I just found the Gm PIDs on torque and tried to match Les' gauge best I could and did a little drive around. I will try to figure out and get a screen of the O2 sensors.
1-4 are at idle after about 3 minute warm up, 4-10 were shots while going down the freeway at about 65 then a side street about 55-60.
I am not sure why these keep showing so large I reduced the image sizes.

 

Attached are a few shots of the O2 dials I could find after warmed up, closed loop, going anywhere between 55 and 65mph.

 

Remember, I said that captured O2 sensor voltages are meaningless because they are swinging rapidly above and below 0.45 volts. Please have mercy - not so many irrelevant screen captures to scroll through.

Strange that you could not get data for emissions readiness (screen capture in post #32)?

 

Please make a Gauge Screen with just these four PIDs selected (immediately below) and take one screen capture at idle - then one screen capture at 2500 rpm steady in Park.

[GM]Desired Idle speed (if not active for your vehicle, then delete this one)
[GM]IAC Position
[GM]EGR Duty Cycle
Engine RPM

Please display a Graph to view the following two PIDs concurrently, over time, and take one screen capture at idle - then one screen capture at 2500 rpm steady in Park.
O2 Volts Bank1 Sensor1
O2 volts Bank 2 Sensor1

Please display a Graph to view the following two PIDs concurrently, over time, and post one screen capture at idle - then one screen capture at 2500 rpm steady in Park.
Fuel Trim Bank1 Sensor1
Fuel Trim Bank 2 Sensor1

6 captures total please. We should be able to give you further direction from these.

 

2500

2500

Idle

Idle

 

This is somewhat strange. At this point I'd say Your O2 sensors are fine, spider nor vacuum isn't leaking.
I'd take a closer look to IAC and TPS. Does Your IAC reading permanently show zero?

 

Yes, the IAC state stayed at 0 parked at idle and on up through to holding at 2500. It never moved even on the 40+ mile drive I just did as well.
Both the IAC and TPS are brand new Delco Parts as of last week.
Regarding the possibility of the spider leaking. What would cause the cleaner area around some spider compared to the very dirty other side? I figured this was the gas cleansing the side, that with the semi rough idle and the horrible MPG it was leaking.

 

That is something. As far as I remember, IAC does not send any feedback signal to ECM, so this would mean ECM keeps it shut on purpose.Question is why?
Any extra fuel than expected (i.e. from a leaking spider) is measured by O2 sensors and would have to be compensated with an adequate air amount to keep the stoichiometric fuel ratio. The fuel trims You have are not pointing any abnormalities in this matter. A horrible MPG may be a result of the problems with high idle.

 

I am at a loss with the IAC not moving, or at least reporting it is moving.
I am about to clear my codes again and manually drop the idle so I can get passed the high idle code and actually be able to decelerate down to 20mph to complete the drive cycles / emissions ready tests hopefully before my retest date.
Regarding the spider leaking it seems to me that may be that the seal is leaking some of the regular pulse amounts of fuel into the top of the lower intake manifold, not necessarily over spraying into the cylinders. This would put raw fuel into the case and I suppose back into the intake and later finding its way back into the intake and throwing of the O2s. How would this effect the fuel trim readings if at all?