Why are there three different alternator belts...? 90-97... 98.... and 99

[AnewDSM]

I need to buy my belts for my build. I am getting all Gates Racing belts but there are three different belt choices.
I don't know what one to choose.
They sell one for a 1990-1997 and one for a 1998 and then another for the 1999...
I have a 1999 block with 1995 pulleys and alternator... Should i be getting the one for a 1995 (90-97) or for the 1999?

I have yet to find any information about this... Why are they different?

 

[monster4g63tawd]

as far as im aware all the 7 bolt blocks are all the same shape i would go with the 90-97 belt seeing as thats the year range for the alternator and pulleys

 

[2GbTalonGuy]

Be sure to go with an OEM belt. Parts store belts like to squeal when installed on our engines.

 

[AnewDSM]

I just bought all of my belts today... Gates.. I hear good things and their fantastic quality.. I went with the 90-97 belt...
the rest were easy to pick out... expensive set of 4 belts.. but that's how my whole build has been.. Expensive...