3G alternator and March Pulleys

[Redfire 05]

I bought a set of March power pulleys for 79-93 stangs, and as I was installing them I noticed a few things.

1) The water pump pulleys are the same size. Why? Shouldn't it be a little larger than the stock pulley?

2) I have a 3G alternator and the stock pulley on it is quite a bit larger than the supplied march pulley. The pulley was of course designed for the stock alternator which it is correctly sized for. So, I left the stock 3G pulley on but I wasn't sure if I should. The car seems to run and charge fine with the stock 3G pulley. The march pulley would spin it faster producing more amps, but I don't know if it would spin it to fast.

 

[bill302]

alot of people leave the stock pulley on the alternator including me on my 95 stang it will be o.k....but the waterpump pulley should be larger than stock...was the crank pulley smaller than the stock and how much...pictures would be good..

 

[Daggar]

If it's charging good with no issues then don't sweat it. Keep that other pulley around in case you ever run into issues.

 

[Mustang5L5]

The stock pulley that comes on the 3G alt is huge. It's like a 3" pulley. This is what comes on the SN95 cars

The Fox Mustangs come with a smaller pulley, around 2.25" or so. You can swap this pulley to the 3G alt if you use a small washer with a 5/8" hole as a spacer.

I run the March pullies with a 3G. I run the crank and WP pulley, but for the alt i run an ASP 1 7/8" overdrive alt pulley. My thinking is that the crank pulley slows down the accesories, but the overdrive alt pulley will spin up the alt more to compensate.

I have no charging issues with an electric fan and decent sized stereo

 

[Redfire 05]

alot of people leave the stock pulley on the alternator including me on my 95 stang it will be o.k....but the waterpump pulley should be larger than stock...was the crank pulley smaller than the stock and how much...pictures would be good..

Yeah, the crank pulley was way smaller than the stock one (not sure how much). I was just worried about the water pump and alternator pulleys. Unfortunately, the pulleys are already on the car (except for the alternator pulley) so comparison pictures would be difficult.