T-56 is about the only thing that will hold up, the TKO 600 needs some help
Liberty Gear magnum XL 6060 (t56 for some of the old timers) starts @ 3550
Rockland Gear T-56/Tranzilla Magnum , not sure what price they are now, the last one I bought was bought for 2016 Hellcat that burned down( fire sale I guess you could call it) paid $1600 for it.

as for 8k, for a trans, if that's what they'll pay then yeah, I know I won't pay that much , hit Ebay there's always a T-56 or Magnum in the 2-3k price range