Yeah.....that was a textbook case of OVERpromise and UNDERdeliver.
There are numerous stories of people waiting FIVE years for delivery, then many customers had problems with the transmissions when NO repair parts were readily available.
I've done two Tremec 5 speed swaps. The first was my own car, the second was when I helped another FABO/FBBO member with his Coronet.
Mine was the last TKO that Silver Sport had in stock, his was a TKX. Mine was done in 2021 and was complete right down to the drive shaft. I paid just shy of $6000. His was in 2023, did not have the drive shaft and way a few dollars short of $7000.
Both kits were excellent, both of us had great service with Silver Sport.