The guys I know that have swapped motors put a tracker body on a jeep frame. More of a drivetrain swap. Small block or 4.3 with a t350 is what I have seen done.
If it was me I would find another running 8 valve, slap it in with a new timing belt and be cruizing in a day. A engine swap will take a lot of time.
Im impressed , I have beat the shit out of a lot of 8 valve motors and never seen one develope a rod knock. Was it run out of oil at some point?