Ok, so I'm new here after recommendation and I've got quite a bit of work to do on the project Felicia, wondering if anyone's successfully upgraded their alternator to 100a plus, intending to run a half decent audio build and really need more than the basic 70a....cars a 1998 1.3 MPI model...thanks in advance

The stock felly alternator with 4 groove belt is 70amp nominal 90 amp peak. 

The 6 groove belted ones are 110 nominal 130 amps peak. 

The issue is the different mounting. 

The first one is used to also tension the belt while the latter is fixed mounted onto the block. 

They ain't interchangeable. 

If you have ac and power steering you have the 110 one if not the 70 one. 

Have a good look here before switching to a new alternator.