I am wondering where to pick up a new one with bigger amperage. I have a 4.3 vortec in a 2000 2 door

 

Why do you need more amps? Have you added a massive thump box? If you are running extra lamps a 125 amp should be sufficient-and thats stock! I have found that one can build their amperage to any extreme,but the factory wiring will NOT handle it! Choose your poison! Good Luck!

 

My alternators going bad and I figured go bigger because I am I'm the process of installing a sound system and eventually lights and a winch

 

How To: High Output AD244 Alternator for ~$80 - S-10 Forum
You could give that a shot.

 

Do ou know how big of a belt I would need for that?

 

I believe it needs to be 1 in. longer than stock. It says in there somewhere.