1968 Barracuda / Hellcat Redeye swap project

trying to get my info straight. doing a hellcat / 6 speed swap sometime soon. trying to figure out the best K member to use. trying to stay budget friendly. lord knows I still have big purchases to make. would prefer to keep the TB but will do disc brakes upgrade (I would like to stop). which is the easier/ cheaper route pre-73 biscuit or 74 and up spool. also I don't want to have to change mounts every other week. thanks for your time.