Thanks guys, i'm having a used with 109k installed next week. Crossing my fingers and toes. Not spending 2,500-3,000 for a rebuilt. Can't. And recommendations on the used install? Flush don't flush? just fill with a new filter? I.d.k
Before installation, I'd remove the pan so you can see what's at the bottom - that more than anything will indicate whether or not it's functional or has problems. Then change the filter, ohm the solenoids and install a Transgo SK4L60E shift kit along with a Sonnax 4L60E LB1 boost valve.
Hydraulic corrections and improvements will help the unit last longer and perform as you expect.
Lastly, install a NEW torque converter - don't reuse an old one, who knows how much contaminants are inside of it.
You're doing the installation?
ETA: Flush your cooler lines and transmission cooler! Ensure you remove all crud from the system. Otherwise, gunk/burnt clutch material may partially or fully restrict return charge and destroy the rear gear train...