Four bolt crank pulley?

pyroman

Founding Member
Jul 28, 2002
480
3
18
Ennis, Texas
I haven't been on here for awhile, but basically I have a new engine for my mustang. 302 out of a foxbody. Now, I have the harmonic balancer that was on the engine (302) however it is a 4 bolt balancer and the crank pulley on the engine in the car is only a 3 bolt (its a 289). I thought this part would be easy and cheap to find, however, I have been having trouble finding one oddly enough. I've been searching online and have come up with pretty much nothing. What kind of cars could a salvage one from? I went to a junkyard yesterday but came up empty handed. The one I have is a three groove because of the a/c, but I'm not certain I'm going to keep the a/c, so that is flexible. Also, what are the dimensions of the one I would need. (i.e. diameter, depth, etc.)

If anyone has one they would like to sell I'd be glad to take it off your hands. :D

Thanks,
Emile
 
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make sure you have the right flywheel to match that balancer... remember the imbalance is different.

try looking for an early 80s Fox. I know 86s have serpentine setup, but I'm not sure about 85 and earlier.

I've got a set of March pulleys on my car that are drilled for the 4 bolt Fox damper. I have a spare crank pulley I might be willing to sell if the size is close enough for you (it's part of a set of underdrive pulleys). It is a 3 groove for AC and PS.
 
make sure you have the right flywheel to match that balancer... remember the imbalance is different.

try looking for an early 80s Fox. I know 86s have serpentine setup, but I'm not sure about 85 and earlier.

I've got a set of March pulleys on my car that are drilled for the 4 bolt Fox damper. I have a spare crank pulley I might be willing to sell if the size is close enough for you (it's part of a set of underdrive pulleys). It is a 3 groove for AC and PS.

Yea i know, thats my next step after i acquire the pulley. I also need to get a new steel gear for the distributor
 
Be easier to just drill the holes in the three bolt pulley to use it with the 4 bolt damper. I did one a few years ago and it took all of 5 minutes to do. As long as the 4 bolt damper has the same offset for the pulley flange, it'll work.
 
THat would be the fastest. CHanging the balancer and the flywheel isn't enough. It is all three pieces-balancer, crank, flywheel. If it's a 50oz imbalance motor, you need to keep it 50 oz throughout. Drill the pulley. Or, I think there was a question about this awile back. I thought there was a place to get a 4 bolt v belt pulley-aftermarket. Or like was said, find an earlier fox with a 4 bolt v belt pulley.
 
You have to be careful with drilling the pulley because the cranks have different offsets. Once you get the piece bolted up, it may or may not line up.

Both of the dampers I posted are 50oz and either 3 or 4 bolt. Both around $100 bucks or less. You can reuse your existing 3 shive pulley. This makes your life the easiest - and IMO it's the cheapest too.

The crank is already 50 oz and is fine.

The flywheel will work fine if you use a late style cable style clutch - or convert to a Daze style hydraulic one. McClod sells a 50oz flywheel that will accept early or late style clutch.

When I did this swap in 1998 I had to use a Romac balancer that was over $400 so I could use the pulley OP is mentioning - none of the less expensive dampers were availible then. I don't think there is an OE piece you can pull from a salvage yard that will work in this application, but I could be wrong. I tried like crazy to not buy that Romac piece........
 
The front snout of all the 289/302/351W cranks are the same. There were at least two different offsets for the pulley flange on the balancers. As long as his 50 oz balancer has the same offset, the redrilled pulley will work.
 
CraigMBA, sorry, I didn't follow the link. I would drill it if it were my own personal car, but if you're not comfortable with that, by all means, get the right part that will simpy bolt on. Will make life easier in the long run.
 
The front snout of all the 289/302/351W cranks are the same. There were at least two different offsets for the pulley flange on the balancers. As long as his 50 oz balancer has the same offset, the redrilled pulley will work.

I suck so bad.........the cranks are the same, the dampers aren't. I can't get my words straight to save my life. Donkeyville for me.

I still say you have to change the damper.

http://www.speedwaymotors.com/p/1802,137_SandB-Ford-Harmonic-Balancer.html

We have balancers available for both 28 oz. or 50 oz. balance small block Fords. They measure 6.4" diameter, are 3" in total length, are marked to 40 degrees at three locations and feature both 3 and 4 bolt pulley holes.
They are made to early style length of 3" to allow their use in tight applications, but adding on with a spacer for pulleys listed below, you can fit almost any car and pulley combo. These spacers are unique and can only be used with the new balancers shown here. Pulley spacers listed are a 4 bolt design, but can be redrilled for the 3 bolt arrangement.

Counter weight is removable for zero balanced cranks. Fits most 260/289/302/351W/5.0 Ford engines.

This engine family used 1 of 5 common length balancers, use the following information to determine your application needed.


3" long, no pulley spacer required, white spacer adaptor ring can be removed from balancer.
3-3/16" long, limited applications, use 91015366 #81006 spacer and machine .090" off of 3 surfaces.
3-3/8" long, use 91015366 #81006 spacer.
3-7/8" long, use 91015368 #81008 spacer.
4" long, use 91015367 #81007 spacer.
 
I installed a ford racing 5.0L crate motor (50oz balance) into my 1968 mustang a few years ago.

(As per CraigMBA's advice) I purchased one of the 3 bolt 50 oz balancers so I could use my existing pulley. I would have to go back through my notes/receipts to determine who I ordered it from. Might have been DamperDudes.net

Note: make sure you use the right flywheel as well. In my case I had the 50oz flywheel that came with the crate motor drilled to accept the early model pressure plate bolt pattern.