351 M: what to do?

[bernardopsilva]

Another doubt I have, my friends...

My 73 was originally a 351 2V, C6 auto ( am I correct?)

A previous owner changed for a 302W, still keeping the trans.

Here, we have much more 302s available, because Galaxies and Mavericks were produced in Brazil.

The question is: I found a 351M (not a Cleveland) for sale here.

============

Is it worth rebuilding?

 

[marks73]

If the Clevelands are not available and you have a good parts supply to 351M parts. Heads and what not. Any motor can be made to run reliably.

One issue you will find is that the motor mounts are about 1-1/2"'s lower than the Cleveland. You will need to make brackets to bring it up or it will not fit the shroud.

 

[hyena429]

If the Clevelands are not available and you have a good parts supply to 351M parts. Heads and what not. Any motor can be made to run reliably.

{thumbs up} And the only bad thing about the 351m is the lack of preformance parts for hot rodders.

 

[jorgem2]

Another doubt I have, my friends...

My 73 was originally a 351 2V, C6 auto ( am I correct?)

A previous owner changed for a 302W, still keeping the trans.

Here, we have much more 302s available, because Galaxies and Mavericks were produced in Brazil.

The question is: I found a 351M (not a Cleveland) for sale here.

============

Is it worth rebuilding?

I would have to respectfully disagree.

The bellhousing is different than the Cleveland and all the other small blocks, the motor mounts are different.

The deck height is taller so the heads will be extremely close to the shock towers.

the heads are junk for any performance type builds

I would say that it is not worth putting in a mustang, Its mainly a truck motor.

 

[marks73]

The motor mount bolt pattern on the block is completely different than the Cleveland. It is a narrower mount and base. They did make a 1 year only 351M400 that had both bolt bosses in the block but they are quite rare (A lot of 4X4's scooped them for the torque).

After considering my earlier post, You can get 1 hell of a lot of horsepower out of the 302 vs the M400 due to (as Hyena429 points out) performance parts are more available and thus cheaper. But we can help you build either one and put a smile on your face. Touque vs Top End

 

[cobra3073]

I agree with Mark's original post. Just about any motor can be made to perform.

Here is a link to a rather in-depth article published by a "Hot Rod" Magazine build-up on a 351M/400 motor.

http://www.hotrod.com/techarticles/engine/hrdp_0702_ford_400m_engine_build/viewall.html

This should give you some idea as to the potential.

BT

 

[Don65Stang]

Have you considered a 351w? I had one and loved it in my 65. Tons of torque & power.

 

[427heaven]

Have you considered a 351w? I had one and loved it in my 65. Tons of torque & power.

Keep looking- Its like trying to compare a ROLEX to a TIMEX or A SPORTS CAR TO A TRUCK!:-/

 

[Don65Stang]

Have you considered a 351w? I had one and loved it in my 65. Tons of torque & power.

Keep looking- Its like trying to compare a ROLEX to a TIMEX or A SPORTS CAR TO A TRUCK!:-/

Thanks for disrespecting my opinion. I know several guys with the so called truck engine that do very well with it. Since the original poster is having difficulties finding a 351c due to his local and since 302s are plentiful a 351w can be built to perform well and use performance heads from the 302 world. Ford basically stroked the 302 block by making it a half inch taller deck. Perhaps where the poster lives the 351w may be a good option for him. I don't currently own one but was very happy with it performance wise when I did. I would rather see a 351c in his car, but given a choice between a 351m, 400m or a 351w; I'd choose the 351w truck engine every time. There are more aftermarket hop ups for it vs the other choices.

This site is about helping one another, not using all caps to shout out your opinion as being better than someone elses. There are many, many other mustang forums on the net where that's the norm. This site is not one of them but truly is the most friendly site on the net.

 

[marks73]

I'm begining to think the heat is getting to a lot of us! :s

Obviously you can only build off what's available where you live. As I stated in the first post, If 351M400's are cheap and available, there are members here who can assist in making it fly as well as possible. Naturally around here in this part of the world, wouldn't be the first option. But internationally, I'll try to help a fellow member make his bicycle pedal faster!

 

[73mach1]

I would go 351w before 351-400M any day of the week because of parts available. If you want 351M you might as well go 429-460 the bellhousings are the same and their are more parts available for this swap and way more power,just my opinion.

 

[Don65Stang]

I would go 351w before 351-400M any day of the week because of parts available. If you want 351M you might as well go 429-460 the bellhousings are the same and their are more parts available for this swap and way more power,just my opinion.

+1. which is why I asked if he considered the 351w. It's a great engine, not my first choice, but a great engine. If it's available in his local then that's what I would put in my car. Definitely more aftermarket parts out there for it. Going to a 429-460 is also a great idea if those engines are common to his local.

 

[OLE PONY]

Have you considered a 351w? I had one and loved it in my 65. Tons of torque & power.

Keep looking- Its like trying to compare a ROLEX to a TIMEX or A SPORTS CAR TO A TRUCK!:-/

Thanks for disrespecting my opinion. I know several guys with the so called truck engine that do very well with it. Since the original poster is having difficulties finding a 351c due to his local and since 302s are plentiful a 351w can be built to perform well and use performance heads from the 302 world. Ford basically stroked the 302 block by making it a half inch taller deck. Perhaps where the poster lives the 351w may be a good option for him. I don't currently own one but was very happy with it performance wise when I did. I would rather see a 351c in his car, but given a choice between a 351m, 400m or a 351w; I'd choose the 351w truck engine every time. There are more aftermarket hop ups for it vs the other choices.

This site is about helping one another, not using all caps to shout out your opinion as being better than someone elses. There are many, many other mustang forums on the net where that's the norm. This site is not one of them but truly is the most friendly site on the net.

Well said Don!

 

[427heaven]

Keep looking- Its like trying to compare a ROLEX to a TIMEX or A SPORTS CAR TO A TRUCK!:-/

Thanks for disrespecting my opinion. I know several guys with the so called truck engine that do very well with it. Since the original poster is having difficulties finding a 351c due to his local and since 302s are plentiful a 351w can be built to perform well and use performance heads from the 302 world. Ford basically stroked the 302 block by making it a half inch taller deck. Perhaps where the poster lives the 351w may be a good option for him. I don't currently own one but was very happy with it performance wise when I did. I would rather see a 351c in his car, but given a choice between a 351m, 400m or a 351w; I'd choose the 351w truck engine every time. There are more aftermarket hop ups for it vs the other choices.

This site is about helping one another, not using all caps to shout out your opinion as being better than someone elses. There are many, many other mustang forums on the net where that's the norm. This site is not one of them but truly is the most friendly site on the net.

Well said Don!

Sorry you took it out of context, typing in caps is not shouting on this end of the key board. Just an opinion with an emphasis on staying away from a truck engine 351m-400m that was never intended to be a performance engine. The little windsor is a different story. After restoring and racing these cars for the past 35 years I was just sharing an opinion on what works for my circle of racers-friends. With enough money and time you could make a barn door fly! Dollar for dollar a 351c will run circles around other engines of similar size buy the nature of the superior cylinder heads.

 

[will e]

So as you can see, it's really down what is available. If all you can find is 351M and you need to do a swap, well, that's probably the way to go.

I tend to keep things as simple as possible so I would hold out for something that I could bolt onto my tranmission (unless your's is going bad). In addition to the 302 you could look at the later 5.0 version. It has the same bolt pattern and there is strong aftermarket support for it.

351M would be one of my last 'ford' choices for the swap. I agree with the folks who say if you are going to go big bell housing you may as well go big displacement. (429,460)

 

[jeffdeq]

351M would be one of my last 'ford' choices for the swap. I agree with the folks who say if you are going to go big bell housing you may as well go big displacement. (429,460)

I think you said it all right there. The 351M/400 uses the same bellhousing bolt pattern as a 429/460. Then there is the exhaust manifold issues, motor/transmission mount supports/brackets, and then a drive shaft. This is why the 71/73 Mustang primarily used small block (302/351C) engines. To change to big block requires a lot of work finding the correct associated parts.

Also, the 351M/400 did not equal the performance of the 351C 4V or the fuel mileage of a 351C 2V. It was introduced to the F150/250 truckline to meet the stricter emission standards of the 1970s. Unfortunately that resulted in lower horsepower and poor fuel mileage for this engine. There was a bit more torque but no one noticed because they were so unhappy about the poor performance. You can make this fit in a Mustang but with all the mods and parts chasing required, you would do better finding an old Lincoln and spend the same on resources to install a 460 4V. A pure stock 460 is a lot of fun to drive in a Mustang. It is the smoothest idling of all the Ford V8s.

My 2 cents,

Jeff

 

[bernardopsilva]

Thansk to all of you, guys.

I read all the opinions, and respect all of them.

As on eof you said, my coices are few, compared to yours.

Yes, here we have much more 302, and we do have some (few) 351C, 351W, 460 big blocks and modern injected 5.0s.

But when you find, expensive and most need total rebuild.

The performance parts are few, even for the 302.

All imported from US, most by request.

What I was thinking most about this 302 to 351M was the looks... of course I want power,

but I really don´t agree to see all that room, in the engine bay, with a tiny small block.

It disturbs me

Bernardo

 

[OMS]

Bernardo, if the 302 runs good and you need to fill up the engine compartement plus want the WOW factor consider ram air

You can also get the tall aluminum valve covers made for roller rocker clearance. It will make the 302 look bigger

Don

Item #3641QX

71-73 RAM AIR, AIR CLEANER BASE

All steel reproduction air cleaner base. Excellent quality, very correct with snorkel, lid and working vacuum door assembly. For 351 Cleveland cars. Includes base, snorkel and lid, no hardware.

Item #3641QY

71-73 RAM AIR PLENUM AND FLAPPERS

Reproduction plenum assembly with working vacuum operated flapper assemblies. Very nice setup.

 

[hyena429]

Thansk to all of you, guys.

I read all the opinions, and respect all of them.

As on eof you said, my coices are few, compared to yours.

Yes, here we have much more 302, and we do have some (few) 351C, 351W, 460 big blocks and modern injected 5.0s.

But when you find, expensive and most need total rebuild.

The performance parts are few, even for the 302.

All imported from US, most by request.

What I was thinking most about this 302 to 351M was the looks... of course I want power,

but I really don´t agree to see all that room, in the engine bay, with a tiny small block.

It disturbs me

Bernardo

If it was me..There is only one other motor "besides my clevland" i would stick in my mustang hands down...429-460 big block...our years of cars where designed around such motors...I agree with wille e on this one....And if you want it too fill the engine bay....and be easy on parts and tons of power....460 big block is the only way to go in my mind