Since researching the build I was going to do, the 3.5L is looking weaker than ever. Nothing to do with capacity mate, my 2.5 can be sleeved out to 4.3L fairly easily. Just letting Simon know that a $1200 stock 3L engine will be much stronger than the 3.5 he is getting and will actually handle the power of twin TD05's.
I made the same error, I have a 3.5 here I wont be using unless I can come up with 4-5k for a rebuild.