Alternator amp upgrade

[KYplumber]

Hey guys, new member, so I hope I'm in the right forum. My wife and I recently bought our '91 GMC C1500 (5.7 L 350) and I noticed the volt gauge showing low voltage. The truck has had a few small issues that could have been caused by this and I'm wanting to change the alternator asap, but I'd like to upgrade from the 105 amp to a 120-140 (nothing too extravagant. Possibly adding an invertor in the future). Will I need to upgrade the fuse block or anything else, or is it just a simple swap one for the other?

 

[jigsaw]

Should be plug and play

 

[kolgeirr]

Hey guys, new member, so I hope I'm in the right forum. My wife and I recently bought our '91 GMC C1500 (5.7 L 350) and I noticed the volt gauge showing low voltage. The truck has had a few small issues that could have been caused by this and I'm wanting to change the alternator asap, but I'd like to upgrade from the 105 amp to a 120-140 (nothing too extravagant. Possibly adding an invertor in the future). Will I need to upgrade the fuse block or anything else, or is it just a simple swap one for the other?

Straight swap assuming you're not going to pull way more amps through the factory fuseblocks. You'll also likely need a longer belt if the higher amp alt has a larger case.

I don't know if it's possible on your motor, but the later Vortec 350s can fit the better AD244 alternators from GMT800 trucks. Might be worth a forum search here to see if anyone's put one on your era of 350.

 

[Nad_Yvalhosert]

The 140 alternator is physically larger, uses a longer serp belt and a different plug connector.
The 120 is a direct swap from the 105.