Can I put a four v intake and carb on factory 400 heads or will I need new heads?

 

Intake will bolt right on. As long as it's a 351m/400 Intake. A Cleveland Intake will require the use of spacers.

 

You can do it but unless you're upping your compression you won't see much return on your investment.

 

Eww...factory manifolds

I'd be searching for a used aluminum manifold before I wasted my time swapping one boat anchor for another.

 

I don't think poster is ever gonna see a factory cast iron 4 barrel intake that fits a 351M or 400. After market, like Edelbrock is all there is ... unless he uses spacers and finds a 351C intake. While the heads are all pretty much the same, the 351M & 400s both have taller blocks than the 351C ... which moves the heads further apart than found on the 351C.

 

Here's what I want to know will the aftermarket 4v intake work with my stock 400 heads?

 

If it's meant for a 351M/400, yes.

What manifold is it? Is there a name or part # cast in it?

 

A aftermarket 4v intake for a 351 Cleveland will bolt to the heads of a 351M or 400, but the intake is too narrow to fit up on a 351M or 400 without side spacers.

The confusion is simply ... as far as I ever heard ... 351Cs often mentioned 4v or 2v heads. With the wider 351M and 400s, no literature that I've ever seen distinguished as they were all Cleveland heads on blocks with 2 barrel intakes and carbs. If you are seeing an intake specified as for a 351C 4v , it has bigger ports and is too narrow for a 351M or 400. Back in the day, Ford was using 4v to mean 4 venturii, and those were specific to a 351C with big port heads.

If you are just looking for a 4 barrel carburetor intake for a 351M or 400, look for a Edelbrock Torquer 400. If you are looking at a intake from Ford saying it's a av intake for a 351 or 351C, it's too narrow for a 351M or 400. Ford never sold a 351M or 400 with a 4 barrel carburetor.

Back in 1979 Prince William Co. bought some new Ford LTD-IIs for police cars, they had 400s in them, but were dogs. The county bought and paid to have aluminum aftermarket intakes with Holley 4 barrel carburetors put in place, it maybe helped them, but they still topped out under 120. Ford had no 400s with 4 barrel carburetors to offer. Those LTD-IIs were as fast or faster than the 305 or 350 Malibus though.

I hope that helps.

 

Yes assuming you mean 4v = 4 barrel. Edelbrock and Weiand still makes one for 351m/400. I have a Holley dominator 4bbl intake and 600cfm street performer carb on my 400m with stock heads and it works great. You can still find the Holley intake used on ebay occasionally.

 

Will a 351C heads and intake with a spacer and intake adapter work on a 400?

 

... damn ...

 

 

351Ms and 400s are Clevelands, they came from Ford with Cleveland heads on them, but because the blocks are wider than "just plain old 351Cs" due to taller decks that move the heads further apart, a 351C intake manifold is too narrow to bolt to both heads at the same time on the 351M/400 block.

 

Weiand Ford 351M 400 Action Plus Intake 1

 

I must be the only OLD FART here that remembers the CLEVELAND YEARS -

When you speak 2V or 4V 351C CYL HEADS it is referring to the runner sizes and combustion chambers design. Put a set of 4V heads on a LT engine and you will lose low end torque.
https://www.diyford.com/351-clevelan...ry-iron-heads/