As far as mods go, you are forced to obey the golden rule. If two engines are exactly the same, the larger of the two will make more power. No replacement for displacement.
If you put a turbo on a 300ci engine and a 400ci engine, all things being equal except displacement, the 400 wins hands down.
You really need to start studying more, your brother is going to be pissed when you lose his cash, or maybe your truck that he *******ly gave you for $11000!
http://www.titantalk.com/forums/showthread.php?t=25386