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Discussion Starter #1
I am looking to communicate with anyone who has installed a 351W in a 67, 68 or 69 cougar (I assume the engine compartment sizes are the same in these model years?). I am considering doing this but have been told by some folks that there will be problems fitting this in plus headers could be a real problem. Has anyone done this that I can learn from?
Thanks.
 

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I did it....not much trouble

I put in a 351W in my first 67 cougar that I had....replaced the 289. Was pretty happy with it, no trouble with the engine compartment or mounts...it all bolted in...tranny and all. The only thing I did after the installation was I put in the 351 exhaust manifolds..it did make a difference in performance than the 289 manifolds. Even though the engine was a little taller, I don't think there were any problems with the throttle linkage or anything like that...all in all a pretty painless swap that boosted performance quite a bit...recommend it..
chris
 

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Discussion Starter #3
Headers

Thanks for the reply. I was also thinking about adding some performance parts (heads, intake, carb, cam and headers). When you installed your 351 in the 67 (which is what I have) was there enough room for a set of long tube headers?
 

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I don't remember really how much room there was...but I did have to remove the heads after the engine was installed and it wasn't that tight...was able to disconnect the exh from the head while in the car....so there may be enough room for headers.
chris
 

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Here's a pic of my cougar on the day I took my 351W home in the trunk...kind of funny
chirs
 

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The 351W is about 1.5 inches taller than a 289/302. other than hood clearance issues if you go to a big manifold and tall carb you only add about .5 inches in width on each side by swapping in the 351W. Considering that some guys are swapping in 390s and 460s I would think that you will have plenty of room.
 

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it bolts in ok but consider the trans is a small C4 likely and the rear end an 8" and no wrap arounds on the shocks like 69/70s have as well as light spri ngs. Its my thinking that if you want 351 to get a body designed for it and the 67/8s simply are not with weaker frt ends trans and rear ends.Kinda a waste of 351 cubes with 289 manifolds. If customs your game headers is way to go otherwise 351xmanifolds would be way better than 289s. 351s a grrreat engine but might be too much for a smaller cat,imho.
 

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Discussion Starter #8
You are correct on the c4 and rear end. The suspension is also stock 67. My intention with the engine area is to get substantially more torque and hp than what the original engine puts out. I do not want to take this car to the drag strip but I do want a fast street machine (throw you back in your seat power when you step on the gas). Do you think a 351 is too much for this vehicle?
 

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351W

The motor will work fine. The problems starts right there though. The suspension will need to be helped. (higher rate springs) The condition of the other components, and the drive train matter alot. a 8" will work, as long as you don't abuse it. The shock towers should be reinforced. I have templates for up to 14 pieces that can be welded into place to help.

The headers will be the only other question. Ford Motorsports and Hooker, among others make standard quality units that should work. Make sure you have your transmission choice set, and purchase accordingly.

I have a 69 351W w/ FPA headers and a T-5 speed manual w/factory bell/linkage.EQ bar setup. Only very minor clearance problems w/ power steering or manual steering. I did have a FMX and Ford headers, but when I swapped in the T-5, the Ford headers would not allow the clutch setup to work.
 

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Headers I have them on my 390 3 words tight,tight and tighter
 

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I did it, but there are issues...

Bolts in, flywheel/flexplate interchange, motor mounts bolt up, etc...

Two different harmonic balancers...3 bolt and 4 bolt. My car came with a 3 bolt balancer so I used an aftermarket 289 balancer so my pullies lined up.

The standard 67 alternator bracket will work IF you can locate the "69 only" bracket that bolted to the head... A "T" shaped bracket bolted to the R.S. head the alternator bolt screws into...

I searched and searched for the correct AC brackets, finally found the base bracket from an 83 E150. Modifed the upper bracket to work.

Car has manual steering, I didn't have to deal with that!


Your 289 front cover, harmonic balancer, and water pump will all bolt to the "W" motor...
 

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I did the 351W swap in my 68 a few years ago. Bear in mind that my whole car is customized so a lot of the modifications I did to make it work are not an issue if you don't care about originality. Also, it might actually be easier to go with a stock v-belt and pulley system.

First of all, I feel this engine was the best mod I've made to the entire car. I can't believe that the weight difference over a 289/302 is great enough to persuade you to look at a different platform. I do know that 69s came stock with a 351W.

I'm also running a C6 which was a freebie and I purchased a 9" for $100 so strength in the rest of the running gear was not an issue. I know that a C4 will live just fine behind a 351 if it's built right. The 8" might be another story depending on how strong the motor is.

I'm running Hedman Long Tube Headers that I ordered for a 69 with a 351 and they didn't fit when bolted up. All long tube headers I've seen have collectors that angle in toward the trans on a Cougar. That's nothing that a porta-power can't fix which is what I did. I also had to dimple the one tube closest to the steering box.

Now, my steering box is 1978 Toyota... not a typo. It is a power box that I made fit by shortening the steering yoke about 2 inches and notched both the frame rail and shock tower for clearance. After this, two of the original three mounting holes lined up. If going with the original power steering, different mods are needed to clear the header tubes, like moving the slave cylinder. I can't offer anything on manual steering.

I'm also running a serpentine belt system since my motor is a 94 and the water pump was set up for that. My power steering pump, and air compressor as well as pulleys and brackets are all 88 T-Bird.

Yes, the 351 is taller and the bracket for the power steering pump and compressor needs to be modified to reach the threaded holes in the cylinder head. I'm also running an Edelbrock Performer RPM Manifold and 4" K&N Air filter. The hood won't close with these items but I was already running a functional cowl induction hood scoop so that wasn't an issue either.

Motor mounts are exactly the same but I did slightly modify the throttle linkage a little to the right side to clear the back of the hi-rise manifold. It was getting hung up.

One last modification was some sort of restraint system on the driver's side of the motor. Yes, the torque is considerable more and I did break my first motor mount. I'm running a short length of chain and a turnbuckle (for tension adjustment) down to the subframe rail. With the serpentine belt accessories in place, this is not even seen but works very well.

I have a picture of my finished motor installation in the 68 gallery.

http://www.mercurycougar.net/gallery/showphoto.php?photo=1160&papass=&sort=1&thecat=502

Sorry for the long post but hope this adds to all the other great advice you've already received.

Mark
 

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289 - 465 lbs
351 - 525 lbs
390 - 625 lbs

A 289 to 351 swap should not require any suspension mods. These things will put you well under 465 lbs.

Toss the cast intake for an aluminum one.
Use lightweight aircleaner.
Use shorty 5.0 style headers.
Move battery to trunk.
Use newer Mustang style plastic radiator.
Remove 1 horn.
Keep windshield washer 1/3 full.
Use Fox Mustang power steering booster.
Use 3.8 starter.
Aluminum heads?
Stay away from heavy chrome accessories.
 

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shouldnt tossing the intake alone save damn near 60 lbs? that iron one is friggin heavy
 

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67xr7, I have a 68 Mustang that I installed a 351W in. it fits fine .Although like some of the others said you will need to upgrade your springs, or up date them with new ones. Do not try to install 390 springs! I tried this, and the front of the car was so high it looked like there was no engine. I just put in springs for a 68GT 302. It sits and handles very well. As for headers, Hedman makes a shorty header exactly for this swap. I cant remember the part #, but I bought them from Jegs. If I can locate the part number I will post it. I didnt want the long tubes because I didnt want to drop the PS bracket. I also installed a C6 Transmission. My C4 didnt hold up so well. Good Luck!
 

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LIZARDKING said:

Use newer Mustang style plastic radiator.

Use Fox Mustang power steering booster.
Use 3.8 starter.

Stay away from heavy chrome accessories.
LizardKing,

I'm hoping you can fill in some details for me on these ideas. I need a new rad in my Cougar soon, what year and engine Mustang does this lighter plastic radiator come out of? Does it require extensive mods to get it into a Cougar?

The Fox Mustang power steering booster, same questions, what year, what engine, do I have to mod the brackets?

The 3.8 starter, are you referring to the 3.8 V6 that is in 94 and up Mustangs (I think?)? Wouldn't it have a solenoid mounted on it instead of on the firewall like our Cougars?

By heavy chrome accessories, do you mean valve covers and such? Are these really heavier than the stock stuff?

Thanks a bunch!
 

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Discussion Starter #17
Thanks for all the input. From the responses I have recieved there are definitely others who have successfully installed the 351W in the 67 frame. As long as I don't run it flat out every time I drive the car I believe the C4 and rear end should do for now. I was also thinking about installing a performance package to the top end. This would include aluminum heads (edelbrock performer heads with 1.9" intakes) dual plane intake manifold and some manufacturers (?) carb. Any experience out there about whether I will have any hood clearance problems? I do not want to have to modify the hood.
 

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Discussion Starter #19
Thanks for all the feedback. From the input recieved it appears there are lots of people that have successfully installed the 351W in the 67 frame with not much problem. I was also thinking about adding aluminum heads, dual plane intake manifold and carb. Any experience out there on whether or not there might be any hood clearance issues?
 

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1967xr7 said:
Any experience out there on whether or not there might be any hood clearance issues?
I have the Performer RPM manifold and a HiPo repro breather.... Clears fine!
 
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