Crankshaft pulley

It may just do that slighty,try getting a new spacer (get a Ford one,dont buy thous cheap ass Profesional Products trash ones they dont line up nearly as well).

Begizzle said:

Where is the spacer? I thought that the crank pulley bolted directly to the harmonic balancer.

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The Ford OEM balancer does. Aftermarket balancers use a spacer to make them fit on many different cars.

Plan on having charging problems and possibly overheating problems using the underdrive pulleys. A different radiator and alternator are often needed to fix the problems the underdrive pulleys create. If you want maximum reliability from the car, look elsewhere for ways to make extra power. An electric fan will increase the HP about the same as the underdrive pulleys, but without the problems associated with them.

On a budget? do the junkyard upgrade...

Gears - 87-88 T-Bird Turbo Coupe rear axle - disc brakes and 3.55 or 3.73 gears in one package for $125-$300. Add another $100-$200 or so to complete the brake upgrade.

94-95 Mustang GT MAF - $40-$100. It is 70 MM instead of the stock 55 MM on regular stangs built prior to 94. It uses a slip on duct on the side that goes to the throttle body and a 4 bolt flange on the other. You need a flange adapter to fit the stock slip on air ducting that goes to the air box. Wiring plugs right in with no changes. *1 *2

95-97 Ford Explorer intake manifold & throttle body $150-$300. The intake manifold flows 220 CFM +, much better than stock. Throttle body is 65 MM, bigger than the 60 MM on stock stangs. I got a 96 with EGR passages that match the stock setup, so my smog gear works just like factory. You’ll need a 65 MM EGR spacer & new gaskets for $65-$90 so you have a place to mount the EGR & throttle linkage.

3G alternator from 94-95 Mustangs or other Ford. $20-$120. A must have to make the electrical system work like it should or if you have an electric fan. You’ll need a 4 gauge power wire and a 125-135 amp fuse to go with it about $15- $30.

Lincoln MK VIII electric fan -$40-$160. Free up some HP by not having to drive the stock fan. The 3G alternator upgrade is a must have prerequisite before you do the MK VIII fan. You won’t have enough electrical power if you don’t do the 3G upgrade.

Aluminum driveshaft: (courtesy of shawn13) It needs to be from a 92-93-94 Aerostar AWD and you will need the u-joint, part #353 from NAPA. It should bolt right up after the u-joint swap.

*1.) Metal flange adapter http://www.kustomz.com/cat3.html Buy the TR70 for $44.95. Or spend some time on eBay looking for one that may fit.

*2.) MAF & sensor interchange
The 94-95 Mustang 5.0 MAF & sensor is also found on:
1995-94 Mustang 3.8L F2VF-12B579-A2A,
1994-92 Crown Victoria 4.6L F2VF-12B579-A2A,
1995-94 Mustang, Mustang Cobra 5.0L F2VF-12B579-A2A,
1994-92 Town Car 4.6L F2VF-12B579-A2A,
1994-92 Grand Marquis 4.6L F2VF-12B579-A2A,
Evidently the –A1A, -A2A, AA, etc. on the end of the part number is a minor variant that did not change the operating specs. You should be able to ignore it and have everything work good.

I only had charging problems with my stock equipment at night when I was running lights, stereo, and or heater. Other than that, your car needs only enough charge to spark the ignition and run brake lights etc... Good mod IMHO and have done it to well over ten cars without problems. You will want to eventually do all the other expensive mods previously mentioned but UDP are a great bang for the buck.

Were the pulleys used or new?

I would never do underdrive pulleys again except for 93 cobra pulleys

Same here, killed two different batteries running underdrives. F-dat.....

93tealstang said:

Same here, killed two different batteries running underdrives. F-dat.....

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Thats crazy we had such different experiences... I have kept the same battery for four years of owning the vehicle, all with UDP's on....

fiveohwblow said:

Thats crazy we had such different experiences... I have kept the same battery for four years of owning the vehicle, all with UDP's on....

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It is a function of where you live and the weather, and traffic conditions. Live in Maine, drive durning the daylight hours in dry weather with no stop and go traffic and you will have no problems. Live in a big city in the south, southwest or desert west and you can expect trouble. Add heavy traffic, heat and humidity and watch the coolant temp rise and the battery voltage fall.

My car simply rejects underdrives. Stop and go type traffic, stereo, and driving at night alot are mainly what caused my battery failure. Bolted stockers back on and haven't experienced even the slightest of problems.

I've heard guys saying they've ran them for years without problems, it baffles me just as it does you that I can't run them.

jrichker said:

It is a function of where you live and the weather, and traffic conditions. Live in Maine, drive durning the daylight hours in dry weather with no stop and go traffic and you will have no problems. Live in a big city in the south, southwest or desert west and you can expect trouble. Add heavy traffic, heat and humidity and watch the coolant temp rise and the battery voltage fall.

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That definitely makes sense and I agree those will add duress to any strained system. Three of the four years of owning the vehicle I was in the high desert and was always running ac... I guess as the last poster put it its just baffling... I say it never hurts to try in the end becuase you can reverse it. If your battery dies after using them for a short amount of time, chalk it up to the cost of the hobby, but in all reality if that is all it takes to kill your battery then you were in the running for a new batt or alt. anyways...

Since we're on the top, what does everyone thing the best brand of pulley's are?

Pullies are pullies no matter what brand, they all do the same thing. Lots of guys running them usually have ASP or March's.

March has the best reputation and for a good reason, however I have always installed Mac and done very well.