351/400 Ford

[Darkmoumoute]

I just bought a 1979 Ford Bronco and it got a 351/400. My question is: is it a 351, a 400 or a little bit of the two.

Thanks!

By the way, pics of the truck will follow later this week.

[min301]

Re: 351/400 Ford

You'll need to get the casting#'s, block stampings, and if all else fails,
measure bore and stroke.

[Darkmoumoute]

Re: 351/400 Ford

Surprisingly, the guy who sold sold it told me that a 351/400 was a 400 block with 351 heads, so in regards of your reply, he was wrong!

Thank you!

[milner351]

Re: 351/400 Ford

I'll have to go back and look at a couple of my books, but as I recall, the "400M" is a 351C with a big block bellhousing (same as 460 as I recall) and a taller block - with a modified set of 351C2v heads, the deck is taller (sort of like a 351W compared to a 302) it takes a different intake manifold than a 351C because of the deck height.

The 351M/400 as I recall, is a 351 cubic inch displacement, but in the same block as the 400 with the big block bellhousing as well ---

Hopefully somebody can correct me here - I'm not 100% on any of this - have to dig out my books to confirm.

[fabricatordave]

Re: 351/400 Ford

351 m 400 m are just weird ,460 bell there own heads and intake and kinda gutless. heard one guy say once that 351m had the power of a 302 and the weight of a 460 .there quite heavy for there cubic inches

[Darkmoumoute]

Re: 351/400 Ford

Thanks a lot for your detailed reply!

[Huskinhano]

Re: 351/400 Ford

The 400 came out in 71 IIRC. It was based loosely off the 351C block but having a big block bellhousing, I believe big block engine mounts and a taller deck height for the longer stroke. It also uses bigger bearings as well and basically uses open chambered 351C heads. The engine was built by Ford to offset lost power of the smaller engines to the early em mission requirements that killed power. It also was intended for trucks and LTDs.

The term 351M I believe came because it was a "modified" version of the 400 using a shorter stroke crank. The problem with the 351/400M is that they were designed to tun on crap gas and have a very low compression. Cylinder head technology back then isn't what it is today, so as a result you have an open chambered head that has poor combustion efficiency coupled to low compression and a small carb and poor flowing exhaust ports giving the 351/400 a bad rep. Years ago Jack Rousch built up a 400M for his Cobra kit car. He stroked it to 460 with an early set of aluminum set of 351C heads Ford use to sell. There's no reason today not to build up one for the street. You could use any aftermarket 351C heads, even the Aussie 351 heads. There are some aftermarket intakes as well. About your only problem is to find a readily available good piston to build some compression.

[min301]

Re: 351/400 Ford

HR or CC did one nottoo long ago.

Coirrect, they share the 460 bell, and mounts, with a bastard block,
Cleveland 2v OC heads. Stock they are a pig, but respond well to mods.
Oiling system is weak, I really would recommend a 351w, or 460 for performance
applications.

[min301]

Re: 351/400 Ford

It can be made to work.
I'm not a fan.