Had to fabricate another rear engine mount crossmember, the first one I made to clear the A/C compressor ended up too far away from the factory 912 engine mount brackets - so I decided to get rid of the A/C compressor and it's heavy cast iron bracket (saved 35 lbs) and simplify things.
I used an aftermarket tubular crossmember that's made for swapping transmissions into hot rods - it's nice and strong, and the bend in it clears the SHO oil pan perfectly. I fabricated plates to bolt to the sides of the engine block and the brackets between them and the crossmember, and used round tubing to attach the ends of the crossmember to the factory Porsche engine mounts.
I ordered a custom flywheel from Kennedy, it will bolt to the SHO crank, mate with the original Porsche starter, and allow the use of a 228mm (9") clutch disc and pressure plate. I also picked up a set of 30mm diameter rear torsion bars, which will be needed to support the added weight of the iron block V6.
I fabricated an adapter plate to bolt the SHO block to the bellhousing of the 901 transaxle out of 5/8" thick 6061 T6 aluminum. It wasn't complicated but having to clearance a "pocket" in it to clear the bolt-on breather at the rear of the SHO block was a little tricky, and I ended having to use countersunk bolts for two of the plate-to-transaxle mounting holes to clear the breather and the SHO oil pan.
Once I had the engine mount done, I bolted the engine in to the Porsche and raised the entire vehicle on my 2 post hydraulic lift to find the center of gravity - it ends up right at where the rear torsion bars are located, which is pretty far back. I had to put some weight in the trunk (battery and spare tire) to keep the car from teetering on the lift arms.