351m/400 engine???

[A67StangMaster]

I got a 351m/400 engine out of a 78 ranchro gt dose anyone know anything about this engine?
How dose it compare to the 351c?
could you fit it into a 67 coupe?
can you make it a proformace engine?
I found some stuff on it but not a hole lot?

 

[Gud T.B. Blown]

I got a 351m/400 engine out of a 78 ranchro gt dose anyone know anything about this engine?
How dose it compare to the 351c?
could you fit it into a 67 coupe?
can you make it a proformace engine?
I found some stuff on it but not a hole lot?

is it a 400 or a 351M, there's a big difference. the 400 is a taller decked version of the 351C. the heads will interchange as will pistons and cams. the intakes won't interchange because the valley is wider. you can build a performance motor but your options will be limited. stay away from the 351M. your best bet is to find a 351C block and build that instead.

 

[yeloxr7]

You will also need a transmission from a 351M/400 application. They have a different bell housing pattern from a small-block or 351C.

 

[67P51]

351c/m/400

I have a 351C in my 67. Fits OK, but with an M having 1/2 inch taller deck height, and thus wider, look out for real tight access to plugs,headers,etc.
351M is a destroked 400 block.
As stated above, performance parts are limited and not cheap.

 

[rbohm]

I have a 351C in my 67. Fits OK, but with an M having 1/2 inch taller deck height, and thus wider, look out for real tight access to plugs,headers,etc.
351M is a destroked 400 block.
As stated above, performance parts are limited and not cheap.

actually the 351m/400 block is 1.1" taller than the 351c block (10.3 vs 9.2). as for performance parts, cams are the same as the 351c, as are rocker arms, and valves. pistons are different only in deck hieght, but are available. intakes are the problems, but again they are available at a reasonable price, BUT you wont find any victor jr intakes or stuff like that as these engines are designed more for low end grunt than high rpm power. you can build a 351m/400 for reasonable money and make around 400hp with a 400(for the 351m just get a 400 crank and pistons, use the 351m rods and block) for around $2k. this engine however will be a snug fit in a 67-70 mustang, much like a 460 would be. you will however have to make headers for the swap as the aftermarket is thin on things like that for the 400. too bad too because it is a good engine for the street.

 

[65ShelbyClone]

Alot of the main points have been covered already, but.....

-The 351M/400 has 429 engine mount and bellhousing patterns; the 351C has 302 mount/bell

-Aside from the taller deck height, the M/400 has 3" main bearings; C has 2.749".

-You can put a 351C intake on a M/400 if you get intake spacer plates. They are still readily available.

You can make a 400 into a stout performer, but many would argue that a 351C is money better spent. I have heard many times that the 400 is a great truck engine with lots of torque