I have a '01 GT with 140K that lived most of its life driven by a grandma that's now in assisted living. It's had an easy life. I bought it a few months ago and have serviced EVERYTHING. I also drive this car very easy.

It runs and drives perfectly, except...I'm beginning to experience mild surging in 4th with the TCC locked. Other than this, it shifts and drives perfectly. I understand this is a common issue. I'd like to correct it before it gets worse. My research has suggested that I should replace the following

1. PCS
2. TCC solenoid

What about these items?
3. Sonnax TCC Apply Valve Kit 84754-43K
4. Sonnax Regulator Apply Valve Kit 84754-34K
5. Both shift solenoids
6. 4th clutch hub
7. Hardened 4th shaft (cookie cutter)
8. Pump shaft
9. Channel plate gaskets

The moral of the story, I want to do it right and fix any weak links while I'm in there. It's not worth trying to save $100-$200 and risk having to do the work all over again.