Engine mounts are easy, can be as simple as pieces of tubing with plates welded to the end sitting on hockey pucks. Look at some of the 16-valved 99 threads on SaabRally.com. They can be made of boxed sheet steel too.
Just hang the engine in the engine compartment from a hoist and get it to sit right, and just connect the dots from suitable places on the block to the stock mounting points under the hood.
(Former) Saab Tech / Competition Prep