Alternator question
 

I am thinking about getting a new alternator because mine is squeeling like hell. My question is if i choose to go with a higher amperage alternator is the plug the same for all the amp ratings? are they all just plug and play with maybe a larger belt?

On my 2000, I went from the stock 105 amp to the optional 130 amp.
Same plug...clocked the same...
slightly larger case...from 135mm (5-3/8") to 145mm (5-3/4")
I didn't have to change belt length...
tensioner made up for the slightly different pulley location

For your 2005 GMC 5.3L, it appears that you can go from a 145 to a 160 amp w/ no issues either.
Just compare the two at the parts store...if they don't have both, have them order them so you can compare before purchasing.

thanks....my tensioner is maxed out right now...i am running two 100mm idlers and a 100mm on the tensioner

I went from the 105 on mine to a 200. It has the same case as the 145amp alternator, and I did have to change belt sizes. I just got a belt for the 05+ with the 145 amp.

The '05 came with a 145 or a 160...not sure you'd see enough difference between the two.
105 to 130 on mine was well worth the few extra bucks.

I upgraded my 04 to a 145 amp with the same plug. Came with a 105 amp...well at least when I got the truck used it was on there..lol

On my 99 i got a 3/4 ton alt that had the plow package, it is also a 160 amp. It has the larger case, but my stock belt fit, it was a little tighter, but still went on easy.