[EvanZR1]

I have not had a trans issue (thankfully), but having had to do and LT5 rebuild, I’d treat the ZF the same way. Do NOT cheap out and use someone who knows what they are doing. My advise would be either send it to Bill or find a used stock (or ideally a Bill rebuilt) ZF. Used ZF will save you some money and let a local shop do the swap, but of course you now run the risk of eventual failure on the replacement. Having said that, there are a LOT of ZFs out there in base & ZR-1 C4s that have had no issues, so used is probably an ok option. Personally, I would absolutely go the Bill route if mine ever has an issue.