Check the tailshaft bushing in the case first. If that bushing walked and spun the case is no good.
When Goodwrench rebuilds 4L80-E I am fairly sure they update the overdrive roller clutch to the 2001+ design with the smaller rollers and blue alignment shoes. It's supposed to prevent the rollers from skewing and flat-spotting from slipping. In practice the smaller rollers handle less torque than the old larger rollers. the 2001+ design has a specific overrun clutch housing and overdrive planet carrier so you can't just replace the rollers.

Pre-2001 (stronger) design overdrive roller clutch:


2001+ overdrive roller clutch:

 

I def have the pre 01 but the housing is chewed up pretty good. What is the exact name of this so I can order a new one, I doubt this one can be re-used

 

I believe that is the front planet.

 

Yes, reaction carrier assembly.
There might be a line pressure problem with this trans. Reverse commands full line pressure because that band has to hold against a huge amount of torque to reverse the output rotation direction. If the pump or valve body cannot produce the pressure needed it will slip in Reverse and burn. You end up with that pictured. I am guessing the reverse band clutch material is blackened, hardened, brittle, and chips away easily if it hasn't already.

 

anyone have one laying around or know of a place to get one that wont be ridiculously expensive? for some reason this trans doesnt have any wave plates or theyre just flattened so bad you cant tell. I plan on running the TransGo HD2 and i believe they require the wave plates. Is it two that I need? The hd2 should solve any valvebody pressure issues once I go threw it. With the pump, its just seals and gears and that should freshen her up? let me know if this parts list sounds about right for a rebuild:
HD2 shift kit, reaction carrier assembly, pump gears, bands, bushing kit, bearing kit, thrust washer kit, gasket/ sealing ring kit, filter. I already have clutches and plan on just cleaning and re-using steels. Wave plates? Oh and this thing has to be either a 97 or 98 with the 1" band instead of the 99+ 1.25"