Scott & Jim there is a classified link at the top of the page for you to use to buy and sale.

We would like to keep this list to help our fellow owners find remidies for their problems.

Thanks

John

 

>matt, the pistons and rods are the
>same i will mail you pistons
>and rods if you beg to
>differ.


I have yet to have one of these engines apart so I will just agree with you..The only thing I really know about the M's is from what I've read on this site and the wlrjet site. I do believe I read that "do to the half inch shorter stroke of the 351M (compared to the 400), the piston decks had to be raised a half inch to keep compression correct." I mean, not to say your wrong, if you think about it, they have to make that half inch stroke up somewhere, right? The only place tey can do that is the piston deck, the rods, or the block deck.

 

>>matt, the pistons and rods are the
>>same i will mail you pistons
>>and rods if you beg to
>>differ.

> I have yet to have one
>of these engines apart so I
>will just agree with you..The only
>thing I really know about the
>M's is from what I've read
>on this site and the wlrjet
>site. I do believe I read
>that "do to the half inch
>shorter stroke of the 351M (compared
>to the 400), the piston decks
>had to be raised a half
>inch to keep compression correct." I
>mean, not to say your wrong,
>if you think about it, they
>have to make that half inch
>stroke up somewhere, right? The only
>place tey can do that is
>the piston deck, the rods, or
>the block deck.



Matt, you're right on this. The 351M connecting rod is the same as the 400s. The compression height, the distance from from the wrist pin-bore center to the top of the piston, for the 351M is 1.947" and 1.647" for the 400. This longer compression height on the 351M makes up for the shorter stroke. If you stick a 351M piston in with a 400 crank the piston will stick up above th block and if you stick a 400 piston on a 351M crank you will end up with something like 5 or 6 to one compression ratio. Same thing happens if you stick a 390 piston on a 360 crank....really low compression (learned this the hard once)

 

I'll bet that hurt!

 

>I'll bet that hurt!


Yeah, it is my father in laws truck he inherited from his father. His father always said it had a 390 in it so when my father in law took it to be rebuilt that is what he told the rebuilders. Well they did not check the numbers or set the new pistons beside the old one to make sure they were the same.

To make a long story short the truck ran great and would chug away down to 300 RPM but seemed way down on power. The rebuilders were not much help. Finally I started checking number and such and concluded that he actually had a 360 in the truck. So we had a short stroke with a short piston.....rreeeaaalllll low compression. We rounded up a 390 crank and rods (turns out they and the 360 rods are near identical, some say they are) and tore back into the engine and used the 390 pistons the rebuilders put in with the new crank.

Needless to say there were vast improvements with the extra 30 cubes and 3-4 points of compression. We are guessing we went from 5 or 6 to one up to 9 to 9.5 compression ratio. The com 260 cam and Holley 600 vaccuum secondary carb didn't hurt either.

Goes to show you have to do your homework and it is best to do something yourself...we were just lucky they did not put the 360 pistons on a 390 cran......that would have really hurt.

 

ok, both the 351 Modified and the 351 Cleveland are "cleveland" family blocks, however the 351M has the largeblock bolt pattern, while both the 351C and 351W are smallblocks. the stock 351M is set up with V2 heads (2bbl carb), this motor was most commonly found in 4x4's and other work type trucks. the cleveland was set up with V4 heads and was a more high performance motor. all the motors share the same 4 inch bore and 3.5 in stroke, however the 351M has larger crankshaft journals that cause more friction making it prone to overheating.

 

>ok, both the 351 Modified and the
>351 Cleveland are "cleveland" family blocks,
>however the 351M has the largeblock
>bolt pattern, while both the 351C
>and 351W are smallblocks. the stock
>351M is set up with
>V2 heads (2bbl carb), this motor
>was most commonly found in 4x4's
>and other work type trucks.
>the cleveland was set up with
>V4 heads and was a more
>high performance motor. all the motors
>share the same 4 inch bore
>and 3.5 in stroke, however the
>351M has larger crankshaft journals that
>cause more friction making it prone
>to overheating.

Only thing is that not all 351Cs came with 4bbl heads and carb. Many of your Mustangs, Cougars, Torinos, and Cyclones came with two bbl heads and carbs. These heads were near, if not, identical to the two bbl heads used on the 351Ms and 400s.

And don't forget that the 351M and 400 both had a 1 inch taller deck height and different motor mounts than the Cleveland...even though they are all in the Same engine family.

Just a little bit more than confusing I admit...but that seems to be the way Ford likes to do it. Keeps the competition guessing.

 

Ain't Fords fun???

Trail Rider

 

thats why the less well endowed "up there" go to Brand X... It takes a real man(or just a great woman) to understand Fords!

Matt

 

I corresponded with the sites owner over the summer. He was indicating that he was starting a new job and the site was going to have to take a back seat for awhile. Perhaps the address changed so that he might cut down on some of the overhead. He had his own domain name prior thereto.


<font color="#f80732" size="4" face="Graphite Light">Stock Man
</font><font color="#0000FF" size="2" face="Graphite Light">1967 F-250 FE 390 4wd</font>
<font color="#0000FF" size="2" face="Graphite Light">1966 F-250 I6 240 2wd LWB Flare Side</font>
<a href="http://www.hometown.aol.com/tbeeee">http://www.hometown.aol.com/tbeeee</a>

 

An easy way to gain some compression & h.p. on the 400 is to switch from dished pistons to flat tops. Like they had when Ford first built them in '71. Have the comparison #'s here somewhere, will post as soon as I find them.

 

I currently have a 351m in my 77 f250 4x4 would a 390 bolt up to my transmission ? it has the 4speed with a granny low . would i have to change my bell housing? what will bolt up to the tranny? i have an extra 351m would it be worth rebuilding?

 

[b]<font color=#b40000>John</font>
66 F100s
<marquee><blink>In the still cool hours of the night, you can hear chevys rusting away. </marquee>

 

Way Keuwl

John

66 F100s
In the still cool hours of the night, you can hear chevys rusting away.

 

Your tranny will bolt up to a 390 with teh correct bellhousing. The 390 and 351 bells are not the same. As to whether or not you should rebuild another 351, that's a personal issue. Lot's of choices and it all depends on money, time and what your trying to acomplish with it all.

<font color="#f80732" size="4" face="Graphite Light">Stock Man
</font><font color="#0000FF" size="2" face="Graphite Light">1967 F-250 FE 390 4wd</font>
<font color="#0000FF" size="2" face="Graphite Light">1966 F-250 I6 240 2wd LWB Flare Side</font>
<a href="http://www.hometown.aol.com/tbeeee">http://www.hometown.aol.com/tbeeee</a>