1966 Mustang Coupe With 302 Engine

metsguy69

New Member
Feb 15, 2018
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#1
New member here.
Recently purchased a 66 coupe with a V8, thought it was a 289 as the VIN indicated. The car didn't run at the time of purchase, but I did notice the pulleys didn't line up correctly. Figured someone installed an incorrect power steering pump at some point in time.
I got the car running, and immediately heard the grinding noise from the water pump pulley rubbing up against the lower pulleys on the balancer.
After doing some research, I found the car has a 1972 302 engine that I verified through the block casting numbers. The alternator and brackets, power steering pump and bracket all appear to be from a 1966 289 engine. The engine runs good otherwise, however I can't see the timing marks (on passenger side of motor) as they are blocked by the brackets and lower radiator hose.
After talking with a few seemingly knowledgeable Mustang guys at a local cruise night, seems it was common to swap an old 289 with a 302. Was told I have 2 options to correct these issues.
Option 1, change over the alternator, power steering pump, and all brackets with early 1970's 302 components. Everything will line up correctly, though I still may not be able to see the timing marks.
Option 2, replace 302 balancer/lower pulleys, timing cover, water pump with mid 1960's 289 components. Everything will line up correctly using my existing alternator, power steering pump and brackets, and the timing tab will now be on the driver's side of the motor. Was told the 289 balancer and pulleys are smaller, giving me the proper spacing so that the pulleys would no longer rub together.
Sounds plausible to me, but did notice the 302 balancer is much larger in size than the 289 balancer and was concerned that the car would run normally that way.
Sorry for the long winded post, but wanted to get all the info out there.
I can't be the only one to experience this. Anyone out there know if option 2 will work? I prefer to keep the 289 look under the hood, and be able to use 1966 components.
Any feedback will be greatly appreciated.
Thanks!
 
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General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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#2
Welcome to stangnet, let me take the first step by moving this to the classic forums and the members over there can chime in with some suggestions, post some pics too of that pully system, that maybe helpful, dang, give us some pics of the whole car, we love to see pics.
 

tos

SN Certified Technician
Apr 27, 2001
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Cincinnati Ohio
#3
You'll want to verify the proper Imbalance of the harmonic balancer. If that is truly a 72 motor and the didn't replace the crankshaft then it should be a 28oz imbalance. If they put a later model crank from the 80s or some aftermarket crank, it could be 50oz imbalance. The balancer needs to match the crank and flywheel imbalance.
 

metsguy69

New Member
Feb 15, 2018
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#4
You'll want to verify the proper Imbalance of the harmonic balancer. If that is truly a 72 motor and the didn't replace the crankshaft then it should be a 28oz imbalance. If they put a later model crank from the 80s or some aftermarket crank, it could be 50oz imbalance. The balancer needs to match the crank and flywheel imbalance.
Hey thanks!
Guess I need to see if a 289 balancer is 28oz imbalance as well.
Thanks again.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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#5
I think you also need to pay attention to 3 or 4 bolt balancers for the pully, somewhere between the 289 and the 302 they changed,
 

metsguy69

New Member
Feb 15, 2018
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#7
Yes, thanks. I did notice that. Its my understanding that the 289 pulleys have 3 bolts and a smaller circumference than the 4 bolt 302 pulleys. Thanks for the reply.