Hey Thunderbird93, you have to talk to wolfpack radicals. They make the big block engine mounts that you will need. I got the complete engine mount and flywheel for like $60 or something. Not cheap, but you will not regret it when you see the power of a big block in your small rs4. Check out their website below, it has all kinds of cool stuff such as 1/8 foam wheel adapters. You can purchase parts from them directly by emailing them. Check the contact section, it should have their email listed.

URL:
wolfpackradicals.com