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How to tell if you have oem "PULLEYS"

John2002

Guest
Just went through a few web sites on the pro's and con's of underdrive pulleys. I'm wondering if I have them on my car already now, how can one tell? What would the oem size for them?. I've always had low volts when I pull uo to a red light, eslically at night with the head lights on and the turn signal going.
 

Blown347

Moderator
Staff member
I can measure my OEM pulleys but underdrives are pretty obvious, the crank pull is barely bigger then the bolt circle on the balancer and the water pump and alternator pulleys are larger then stock. If you post a picture of them I could tell you
 

John2002

Guest
I'll get some pics out this weekend, I had to move a pile of slush from the rear of my garage...some ayhole with a plow barried my garbage cans so the garbagemen didn't get to me today. Thanks for getting back to me... They look oem but like I said I've had that volt problems since I've owned the car and now after going through the web about it I thinking to much into that underdrive issue.
 

FoxBodyMustangs

Administrator
Staff member
Just went through a few web sites on the pro's and con's of underdrive pulleys. I'm wondering if I have them on my car already now, how can one tell? What would the oem size for them?. I've always had low volts when I pull uo to a red light, eslically at night with the head lights on and the turn signal going.
post some pics...:)
 

John2002

Guest
From the looks of the rust, they seem to be oem pulleys. Just swapped out the Standard coil pack for and Accel coil pack and ran the engine with the head lights, turn signals and defrost on...the volts never dropped below 12. (If thats what the second mark above 8 in the gauage is supposed to be)
 

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Blown347

Moderator
Staff member
Yessir those are OEM pulleys. I'd consider a 130 amp alternator upgrade. The factory one is pretty weak. Even a stock replacement for a 94-95 would be better. They're rated at 95-110 amps depending on which brand. Just takes a little grinding on the bracket to make it fit. Nothing difficult
 

John2002

Guest
Yes it was, as week as a kitten... I got the new alternator last month. PA Performance's has a 95 amp alternator, it should be good enough for my car show driver. The only thing thats not stock on the electrical system is the third brake light in the spoiler I added in 2010. Thanks for the help, my car might get back on the ground next month now, we're supposed to be getting with another 6 to 8 inches of snow and 4 to 5 days more of that "Polar Vortex". I guess Global Warming isn't the hot topic anymore.
 

Blown347

Moderator
Staff member
Yea all foxbodies came with either a 65 or 75 amp alternator depending on year and options, so any upgrade is definitely better. 95 should be fine. If you ever decide to run an electric fan you will need a 130 though so something to consider
 
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