Well I just tested my coils. Secondarys were 6.05, 6.10, 6.15.

Primaries all went to 1.0, but all 3 came down to 0.9 once it sat for 10 secs. Weird.

So as long as the close to 1.0 primary readings are fine, my coils are fine. The car still shudder when the torque converter kicks in. If I tap the break it fixes it until it locks back in. There still remains an odd ringing noise usually happening when the car gears up to shift. Sometime it will build up the ringing noise until I take my foot off the gas. The noise is there while in park and neutral.

My MPG is still anywhere from 13MPG to 16MPG city.

So what am I looking at here bad torque converter? Heres a list as to whats been done to the car so far:

1. Heater Core (Summer 2006)
2. SC drive unit (Fall 2006)
3. 190 Thermostat (Fall 2006)
4. Replaced all hoses (2006)
5. Gas tank (12-28-06)
6. Gas straps (12-28-06)
7. Cam sensor (4-23-07)
8. O2 Sensor – AC Delco (4-26-07)
9. Fixed hood + trunk light (4-26-07)
10. PCV Valve and O-ring – AC Delco (5-9-07)
11. Starter (11-1-07)
12. Oil pressure sensor – Junker (11-1-07)
13. Replace LIM, SC, and TB gaskets. (Winter 2007)
14. Cleaned TB, SC, and LIM in parts cleaner. (Winter 2007)
15. Cleaned MAF Sensor (Winter 2007)
16. Front right wheel bearing (1-11-08 )
17. Monroe Struts, mount, bearings, and boots. – Both front (1-11-08 )
18. Wix Fuel Filter – 128,000 miles (1-11-08 )
19. Turn signal flasher (1-11-08 )
20. ELC Air Compressor relay (1-13-08)
21. NGK TR55 Spark Plugs (1-21-08)
22. Autolite Pro Spark Plug Wires (1-21-08)
23. Removed both rusted support rods from exhaust pipe. Welded a rusted/broken bracket back to the exhaust pipe. (1-21-08)
24. CAI. Rx-4750 K&N Filter. Polished aluminum pipe. Silicone 3.25 to 3 coupler. IAT drilled into filter. Spliced IAT harness for it to reach. (January 2008)
25. Driver door lock actuator - Junker (Summer 2007)
26. Oil Pressure Sensor (March 2008)
27. AC Delco Water Pump (March 2008)
28. Transmission fluid and filter change along with Lucas transmission fix (March 2008)
29. Supercharger coupler and oil (March 2008)
30. Front passenger wheel well splash guard (March 2008)
31. Custom stainless steel mesh put into front grille (March 2008)
32. Fixed snapped T2V power steering connector (March 2008)

I really don't think there is anything else to rule out besides a bad ICM or ICM harness but I can't really test those without plugging in another one. Whats a torque converter cost and how bad is the job?

P.*. Changing the transmission fluid, filter, and lucas transmission fix seemed to help the shudder slightly.

Did a lot of Service bulletin research on this issue and two stand out.
GM has advised techs that:
1) Aftermarket high flow air filter oils contaminate the MAF and could cause the shudder.
2) A faulting TPS that displays a voltage drop / fluctuation while in lockup could cause this.

These to SB'* refer to the 95-96 model years.

Thought I would share a couple of things that might relate:
1. Shuddering - I had that, but usually only if I was also trying to accelerate, even just moderately, in lockup/OD. However, it would also crap out when accelerating hard or gassing it in Park.
2. Coils - Mine passed the resistance checks for weeks. Then it started spitting and vibrating in Park. 2 coils had finally completely died for 1 cylinder each. THEN, the coils flunked the check with complete opens on the output side.

NOTE: I did have several other problems that were slowly fixed along the way. But the shudder and crapping out was the final problem.

x2. Sometimes goes into OD HARD when tc is locked, and that'* when it shudders. Typically if the shift feels smooth, it won't shudder. If it shifts HARD, it'll shudder until you unlock it with 50% or more throttle and don't let it lock until around 55.

EDIT: This is 4th trans and tc in my ownership. I think it'* a sensor somewhere...

I remember reading the SB that said an over oiled K&N air filter will contaminate the MAF ands cause this.
Its worth a try as both you guys have K&N'*.
Also if you have another donor TPS you could swap thats an easy test.
The contaminated MAF could cause clutch damage if thats the case according to the bulletin.

I've tested TPS in all positions, seems to be OK, and was adjusted for earlier kickdowns. MAF was cleaned with a little alcohol on a q-tip when I ported LIM - should I buy a can of MAF cleaner?

Just wanted to add... MAF has been cleaned thoroughly and has made no difference.