[joyridin']

You won't lose much hp if the carb is set up correctly. Maybe 10 hp at the most? If I were going that route, I would probably not buy a 480hp version assuming you were going to buy a crate engine. Buy the 430hp version for a lot less money, throw in a $400 cam and the carb set-up, and you can have 515-525 hp without a problem. You would void the warranty by removing the EFI, so it would not matter.

I would never think about removing the EFI though. LS3 engines have a pretty killer set-up right from the factor and can support close to 600hp on the stock system.