You are confusing overdrive with underdrive. For the alternator, smaller pulley spins faster, so will help at idle.
I can see alternator is a Carquest, maybe Autozone?
OD is the top of the 6 ribs. Most 3G upgrades are too large & won't give enough amps at idle for the Foxbody.
If yours measures 1.9"OD, it is correct. I've been using this ASP pulley for 25 years.
My pulley appears to be smaller than yours.
Belt noise could be pulleys aren't lining up. Might have to put a shim (large washer) behind the pulley. I never had to do this.
BTW, your engine & bay look like new!!! Looks like it's been stored away for 31 years. It must have lower miles than I do.
Still has the plastic cap on the front of the intake. The glue dries up after a couple years & it falls off, It doesn't cover anything, don't know what it was for.
Last edited: