Here is your new engine
http://www.ofna.com/eng-picco-26.html
I never put a big block in a Revo so I can only tell you what I have read....Many people like the New Era bb kit.
You need a 1/8 clutch and clutch bell
If your still using the rear exhaust you will be limited to a header that will work. I know the Trinity pipe/head will work but I can't think of any others right now. I don't think your THS pipe will mount to a big block header.