90 amp alt. VS 124 amp alt.

[oldmansax]

My '99 has the stock 90amp (or maybe 104amp I forget the exact rating) alternator. I need to replace it. My local parts house has the exact same physical size alt in my rating AND 124 amp rating. The only difference is the electrical plug -- the 124 has a different connector. It appears to have the same number of wires. Has anyone made the step up to the larger alt? Where can I get the correct plug? The parts house also has a 150 amp but it is quite a bit larger. I would need different brackets to mount it I think.

[tom.mcinerney]

At a minimum, suggest talk to a local auto-electric rebuilder. They might be able to give an informed answer, and would most likely have (or have access to) the connector(s).
Another prudent option would be to ask local GM dealer parts reps about high output alternator options for the model. Then see if the aftermarket alternator is same type...
Some years have a dual alternator option.

[triggerman]

Last year my stock 105 amp unit's bearings went south , so I found a page under alternatorparts.com and liked the idea of the factory optional CS144 (140 amp) unit since it's out put at idle is allmost what the 105 does at revs. The CS144 is biger (bearings,and cooling rectifyer). The unit will slip into the original cast bracket but I did have to make a bracket for the back. you can make it out of a peice of 1" X 1/8th flat stock, 2 holes and a slight bend. The adapter plugs are on the page also. Or at any alternator shop. Also, I had to swap pullys to keep your TAC workin at the right speed. The serpentine belt also has to be a bit longer to make up for the larger body, use the GM one for the 124 amp alt or Goodyear #4061020 it will have 6PK2590 on the belt. Good Luck with your decision. :cool: