serious clutch slippage woes

[Captainsnus]

Hello All, I have a 2002 Carrera 3.6, 2wd coupe. Its got 84K miles on it and has had 8 owners before I got it. I decided to take it to a well known independent shop here in Portland for a clutch and its service. Before this service the clutch worked fine and didn't slip at all, but was almost to the rivets. After the service I was driving it on the freeway and felt it slip when I was in 6th gear cruising and just mildly accelerating. I took it back to the shop and they investigated, took the gearbox out and put another clutch disk and pressure plate that had more surface area thinking the car was somehow overpowering a stock one. This clutch also slipped so the I started trouble shooting myself. I went through all the clutch system. New flex line from the car to the slave, new master cylinder, new slave cylinder, and it still slipped. I then took the car apart myself and put all new parts in, flywheel, clutch fork, disk and pressure plate with stock replacement parts. I have been driving it gently, ie:under 4000 revs to "break in the clutch" which I know shouldn't really be needed. It seemed to be behaving, but yesterday I took it out for a drive cycle to check on a code reset I did, and it slipped again!!! Ive looked at the clutch assist spring on the pedal and it does not appear to be broken. My last theory is that somehow the slave cylinder push rod is somehow slightly too long and never fully releasing the clutch. the problem seems worse on a hot day. Has anyone out there dealt with this before? Is there a difference in pushrod lengths between 3.4 and 3.6 engines? maybe mine was an early 3.6. Feel like I have some part incongruity. At my wits end! cheers!

[yelcab1]

Did you check the condition of the flywheel?