ok, here it is, I have a 351m in my ranchero
I am just starting to build a 351c...
now my problem. I have been told that the c6 will not
bolt up to a cleveland, and that the c4 will not bolt to
a 351m yet a tranny shop tells me that the tranny in
the ranchero is a c4 and the bolt pattern is the same for
both blocks.
Help befor I go any further on the 351c rebuild.
thanks
sanddoc46(No Email Addresses In Posts!)
please reply to my email

 

Here ya go, 351M has the same tranny bolt pattern as the 400, 390, 460 etc...... the 351C has the same as the the 351W, 302,289, and 300 I-6. the is NO C-4 available for the 351M's and other "big blocks as most people refer to them. I much rather have a 351C over a 351M. IF ya have any questions you can email me at getusum69@altavista.com


Owner of
1969 Ranchero 351W, FMX tranny
1980 F150 4x4 351C and C6 out of a 1974 Ranchero

 

If you do have a c6 then it will not bolt up to a 351c since the 351m has a big block pattern as the post above says.You can use a c6 but will have to use one that has the small block pattern case.
There were some c4's that come from behind 351m's in the late 70's.So if you in fact do have a c4 in your car then you can get by with just changing the bell housing to match up to the clevo small block pattern.

 

The 289,302,351w and 351c use the small block bell housing ,there is a C4,C6 and FMX that will fit, the 351m ,400m,429,and460 have the big block bell housing , the FE's 390,427,428 have there own bell housing. In (I think) 1974 the 351m&400m used the small block bell housing for one year only. So its possible that you have one of those.Just take your engine plate from the 351m and put it on the 351c and see if it lines up.

 

>The 289,302,351w and 351c use the small block bell housing
>,there is a C4,C6 and FMX that will fit, the 351m
>,400m,429,and460 have the big block bell housing , the FE's
>390,427,428 have there own bell housing. In (I think) 1974
>the 351m&400m used the small block bell housing for one year
>only. So its possible that you have one of those.Just take
>your engine plate from the 351m and put it on the 351c and
>see if it lines up.

Apparently only a small number of 400's used a small bell housing pattern, and no 351's that I have heard of. Still worth checking, but the dude will likely have to bite the bullet and get a different C6.

I suggest that he buy a rebuilt transmission where there is a core return, but make sure that they have no problem swapping bolt patterns - I suspect they will have no issue over it...

 

[updated:LAST EDITED ON 12-Jan-02 AT 10:15 PM (EST)]>ok, here it is, I have a 351m in my ranchero
> I am just starting to build a 351c...
> now my problem. I have been told that the c6 will not
>bolt up to a cleveland, and that the c4 will not bolt to
>a 351m yet a tranny shop tells me that the tranny in
>the ranchero is a c4 and the bolt pattern is the same for
>both blocks.
> Help befor I go any further on the 351c rebuild.
>thanks
>sanddoc46(No Email Addresses In Posts!)
>please reply to my email

i'm looking for a c4 with 351m (big block) bellhousing, or even just the bellhousing. i have an FMX with the bellhousing that will fit the 351c - does anybody know if the FMX & c4 use the same bellhousing? if so, maybe we could trade.
bradwebsterNo Email Addresses In Posts!

also, does anybody know the approximate difference in weight between a c6 & a c4, and how much power is lost to internally just turning the tranny? i've heard the c6 is heavy and has much higher "parasitic" power loss than a c4...

 

Ok ,first off the fmx bellhousing wont fit up to a c4.For the bell housing there was one on ebay a week or so ago if that helps any...They do come up there every so often.
For the horsepower loss it's something like 55-60 hp to turn a c6 and around 28hp to turn a c4.

 

woohoo! i'm the guy that got that big-block C4 bellhousing on ebay!

 

On a related topic: My 51F-1 pickup has a 1967 289 2bbl, and a C-4, from a 1967 Ranchero. Can anyone tell me the rear axle gear ratio that was stock for that setup? I mated it to the'51 stock 4:11 Dana 44, and wish I had the '67 Ranchero ratio, for more freeway friendly cruising. Now, I do about 2850 RPM at 60 MPH, I think.

 

>On a related topic: My 51F-1 pickup has a 1967 289 2bbl, and
>a C-4, from a 1967 Ranchero. Can anyone tell me the rear
>axle gear ratio that was stock for that setup? I mated it to
>the'51 stock 4:11 Dana 44, and wish I had the '67 Ranchero
>ratio, for more freeway friendly cruising. Now, I do about
>2850 RPM at 60 MPH, I think.


Ford always seemed to offer a variety of gear ratios, so there is no single 'stock' ratio. There were likely some that were more common than others...

 

>
>
>woohoo! i'm the guy that got that big-block C4 bellhousing
>on ebay!

Why would you want a C4 on a big block? I understand that there is more parisitic power loss (about 28 HP more by some reports) with a C6 over a C4, but I thought that the C6 durability more than made up for it (at least for the street). Are C4's more popular for racing where every HP counts, and durability is addressed by more frequent servicing?

 

[updated:LAST EDITED ON 17-Jul-02 AT 07:53 PM (EST)]>Why would you want a C4 on a big block?

i'm planning to launch hard enough to "hurt" a stock C6, so i'll need a built up unit. so i did some checking around, and it's about $200 more to build a C4 to the same level as a C6. i figure 28 (or even 20) horsepower PLUS the weight difference is worth an extra $200. this ranchero will be doing some drag racing, and aside from that the reduced weight should help handling a little as well. i'm thinking about some other weight-saving mods too, so the C4 just seemed to fit into my plans a little better.

BTW - i'm planning to refer to the 400 as a "small block"!

 

Im looking more in to the C4 vs. C6 my self. I have a 70 with a 302 at one time had the 4:11 but later swapped out for the 3:65. I went through 2 C-4s in less than two years. I wasnt on the drag strip just a heavy foot, The engine had been boared and I had reworked my carb and a few other little things that gave me a litle more power. I had considered going C-6. I got a used C6-FMX which after installing had a busted pump, I also had trouble with linkages. So I am debating on getting a Street/Strip C-6 or C-4 or having my orginal C-4 Rebuilt and beefed up at the same time. Does anybody know if their is a kit for getting linkages to hook up??

Whatcha Think???

David