Oh man... after seeing all those shiney parts... I am so going to take my 4L65 apart just for kicks.

I must get a sick pleasure from attempting the impossible

 

This was February of 2004. Since you've had those clutches in your overdrive for 5 years I must have got bad information. The ones in it since then are what appeared to be stock equivelents - paper type. Honestly, they are holding up great, or I'm not making much for power! I have shifted it at 5400RPM WOT from 3 to 4 an uncountable number of times. (That's barely 100mph in my truck with the GV off.) No change in shift feel since day one of its new life. The 3-4 is lazier than the rest though, that's for sure.

 

It seemed like I fell down the rabbit hole when I saw this pic....

 

I just checked out Hughes Performance Transmission they have Alto Red Eagle and Kolene Steels for the Fourth clutch and Overrun (they are not technical called Alto Red Eagle but they are). This wants me to go out and start pulling the tranny out of my truck and rebuild it.

 

the 3-4 is only thing I'm slightly not happy with. I drilled .096 holes for 1-2, 2-3, & 3-4. Next time I am in there I am going to step up to approx a .120 on the 3-4. Although having a beefed up fourth clutch might be in order as well. And if that's in order, maybe I should go through the whole thing.............see how that works out

 

James- what Raybestos clutches did you use?

the red or the blue? from what I've read the blue look to be race oriented.

Also, anyword about availability of the Z-Pak for the 80? or is this just a 60 thing for now?

was looking at these:
Clutch Pack Set L95-UP w/ New gen2™ Blue Plate Friction Clutches

 

They were the blue plate specials - same parts a TH400 uses.
Most builder are saying hte Z-pak isn't delivering on its promise to last longer and run cooler. Single sided clutches still have problems getting hotter on one side than the other causing warpage. The propaganda said that was all solved through technology but the real world says the Blue Plate specials really do work better. The Z-pak was developed especially for the 3-4 pack in 700R4-based transmissions. No other availability has been announced that I know of.