Bent Frame, bent k member

It would make the most sense to go with a 73 and up V8 K-member, spindle, disc brakes, sway bar, lower and upper control arms. You will get better braking and the calipers will be positioned correctly. If you can’t afford to change to disc brakes just change to the 73 K-frame and you can upgrade to disc brakes in the future. Going with the slant-6 K-member and reusing the motor mount adapters makes no sense to me.