Fo-fever is slang for .45 caliber. The “fever” makes people sick or die. .45 is the main caliber of Thompsons, a gun made famous by Prohibition gangsters.

Gucci had just come home from jail for the “pool stick incident. Unfortunately, he did go back to jail later.

I started out “minor league”(on a independent record label) now I’ve increased my status to being “major league”(on a major record label).
Baseball reference – minor league is a league that prepares players for the higher competition in the major league.

Give me what you owe now, I don’t care about how much you’ve paid in the past. I got this attitude from growing up during the 1980’s a “crazy” time where cocaine/crack selling and the associated violence were at there height.

Two Gucci childhood pop culture references here – “Fuck you pay me” is a quote from “Goodfellas” and “What you done lately” is an adaptation of Janet Jackson’s [“What Have You Done for me lately”]
(http://www.youtube.com/watch?v=r9uizdKZAGE&ob=av3e).

http://youtu.be/5ydqjqZ_3oc
http://www.youtube.com/watch?v=r9uizdKZAGE&ob=av3e

“Scrap” means “strapped” because Atlanta natives often pronounce “t” sounds as “c”. For example, they will pronounce “street” as skreet.

Not only does the navy have big guns, the navy is also known to scrap (tear apart and recycle) old ships that can’t be used anymore.
Scrap also means to fight so he could be saying he fights like the navy.

Your diamonds have low clarity so it’s obvious you’re not wealthy.
cloudy diamond -

high clarity diamond

Beautiful women love me cause of my Southern style and charm. Then he seems to contradict himself by saying his swag is on Northern but Northern means cold, meaning he has a lot of “ice”(diamonds). Nawlins is a Southern pronunciation of New Orleans. In New Orleans, grills(over teeth jewelry) are popular among blacks and often permanent.

New Orleans rapper Baby’s grill maintenance -
http://www.youtube.com/watch?v=LPGXp9iM0KE&feature=related