Thanks for reinforcing my doubt about the repops.There are aftermarket 5-pinion planetaries but I would not recommend using them...I only use OEM GM and acquire them via my local hard parts supplier or directly from a 4L65/4L70 core. I rebuilt a trans once with an aftermarket 5 pinion set and the rear planet came apart after about 2000 miles or so...trans had to come back for re-work / planet replacement...No issues with the install/fill and no lube restrictions in that system...Planet just failed. Replaced with an OEM planet and never heard from the customer again...This was about 8 years ago...
I noticed the repop didn't have the same quality in the finish as the OEM and there is something strange with the pinion thrust washers. If you look closely you'll see the tang hanging out and to me it looks like that tang could sling out into the ring gear and cause a catastrophic failure.