Its been my experience since we've own our Fiero that all remanufactured ALTS come with a 5 groove pulley. I had to swap my 4 groove pulley on to my new ALT. The other difference is, the fan. I'm sure the 88's came with the upgraded disk fan but my original had a blade fan but I liked the look of disk better so I kept it.
If the ALT on your car is original.. Get a metal brush and clean the head of the bolt then use the brush on back side as well. Then SOAK the bolt in PB Blaster. Let it sit for 5 minutes then just use a little pressure. If this bolt hasnt been touched in 25 years you may not be able to move it..(Like mine
) If you have all the time in world to work on it.. Then I would do several rounds of PB Blaster and try to use and IMPACT wrench.
Tim and Lynn
1987 Fastback GT in restore mode..