alright the stock alternator from oreillys was crap so they let me get a 2003 silverado 5.3 alternator instead. It was kind of pain in the *** to make it fit but it did and you might have to extend ur exciter wire i didnt cause i order a new one from ebay. I forget about the pulley and didnt switch it out or have the stock one. The stock belt will not work so I have a buddy who works at auto zone we manage to get a belt that will work. I havent had any issues yet but we will see....

The alternator item number from o reillys is 01-1873 and the belt that works with it that i bought from auto zone is 800k6 hopes this helps some people....... The truck alternator is 145 amps the stock one is 105

 

That sounds great. Why did you you put the 5.3 alt in the first place? Was is just because it was the only one available? This is a ls1 I assume.

 

yea alot of people on ls1tech.com going through alternators like crazy one member went through 10 in a year its all the places like auto zone, oreillys, etc... all the remanufacturer alternators crap out i just put a new one cause of my power steering leak was ruining my alternators put in a new stock one failed in 10 mins so i put a 5.3 of a 2003 silverado but 1999-2003 will work but it dont have the back bolt but it stills works and the exciter wire might need to be lengthin but u wont have anymore problems

heres the thread on ls1tech.com http://ls1tech.com/forums/generation...l#post16697296