After doing some looking around on the site, I have learned that the 4V carb setup was not a factory option for a 1978 with a 400 in my truck. So that gets me to wondering about application. I only use this truck for hauling a camper around, and my gooseneck dump trailer. I'm not interested in going 100 mph, but need best MPG I can get, and good power to get up and go when its time to. I currently have an Edlebrock intake and Holley 650CFM installed. Should I swap out the 4V setup for a 2V?

 

If your holley is working well leave it on. Difference in fuel milage will be minimal and you'll have better power with the 4bbl.

 

A 4V carb was not available on any Ford F100/350 with a 351M or 400 engine (1977/82).

It was not available on the cars with 351M's (1975/79) or 400's (1971/79) either.

351M/400 = 2V carbs only (that also includes 1978/82 Bronco's and 1980/82 Econolines).

 

Thats kinda the problem is that the Holley is not operating correctly. I can't get the secondaries to open up, and have a real idling problem with it during warmup. I'm pretty sure that there are other issues contributing to poor performance of the carb - but I thought that if might have to replace carb, I might as well ask about which would be better. Also, I've been told that if I replace the 4v with another 4V that I should get an Edlebrock and get rid of Holley because they are finicky for everyday drivers?

 

Thanks NumberDummy, good info!

 

A small 4V actually has smaller primary bores that the stock 2V. i.e. if your foot isn't in it you could actually get better milage. The power is there when you need it. On the other hand if it's not working right...............

 

Never say never ! Factory 4V Ford 400 intakes have poped up on Ebay through the years.

 

That looks like a 351C 4v intake to me

 

Not a chance Mil, thats why the tape is on there. It's the 3rd one on Ebay I've seen through the years.

 

Could be some odd aussie setup? 78REDFORD, I'd recommend an edelbrock 600 cfm, easy to tune, gaskets are above the fuel level(no power valve blow outs), and all around good daily driver carbs. 4v will always be more efficient if you don't keep the secondarys hammered alot due to the nice small primarys which are way smaller than any 2v I have seen. Not sure of the new hollys, but the old ones were very finicky, need reset alot, leaked, and would blow the power valve on just about any backfire-tho with patience made good drag racing carbs. I know of a few friends who switched from old holleys to an old or new edelbrock/carter and were very happy.
Good luck!

 

What are ALL the casting numbers on it then ?

Please post them

 

I can tell by looking at it that it's too wide to be a 351C intake.. doesn't mean it isnt' some old aftermarket intake or something.

Also, there have been some rare trucks asked about on here.. special fleet options and whatnot, couldn't they have made intakes for large special orders? or possibly a 4v option they were toying with near the engines end of life that never really hit the gruond (or brochures)

sucks there wasn't internet (as we know it) in the 1970s

 

Thanks Thunderjet4x4......Your the second one to offer that advice. I not even going to pretend to know much about carb tuning - so the simpler the better for me. I'll check into the Edlebrock 4V setup ( about $250 at Napa) and see how it works out for me!

 

I have every Ford car & truck parts catalog that pertains to 400 engines from 1971 thru 1982.

NONE list a 4V intake manifold or a 4V carb for a 400.

The Muscle Parts Catalogs don't show a 4V 400 intake manifold, either.

What is the Ford casting number shown on this supposed 400 4V intake manifold.

What is the Ford ID engineering number from that EGR spacer plate?

The spacer plate upper/lower gaskets also have Ford ID numbers on them.

1965/72 & 1973/79 Ford Passenger Car Parts Catalogs / Section 93 / 9433-Gasket Set, Intake Manifold.

D0AZ-9433-B .. Intake Manifold Gasket Set / Fits: 1970/74 351C 2V.

D0AZ-9433-A .. Intake Manifold Gasket Set / Fits 1970/74 351C 4V.

D1AZ-9433-A .. Intake Manifold Gasket Set / Fits: 1971/74 400 2V.

Where's the intake gasket set for a 400 4V? You won't find one because none exists.

The large secondaries on the EGR plate are exactly the same as used on 1973/74 351C 4V's

The intake manifold looks exactly like the one used on 351C 4V's.

351C, 351M and 400 engines all look identical.

Both have the 8 bolt valve covers, no timing cover, and the fuel pump mounting bolts at 12 and 6 o'clock.

Look around...anywhere, see if you can find a FoMoCo VIN engine code for a 400 4V. You can't because there isn't one.

1973/74: H = 351C 2V / Q = 351C 4V / S = 400 2V. That's it.

I was a Ford partsman for 35 years, so I'm not someone who thinks a 400 4V manifold exists, just because they saw one advertised on ebay!

THERE'S NO SUCH THING!

 

I just showed you the proof. This has been disgused before here. There isn't any sense in argueing, the picture speaks for it's self. A cast iron 4v manifold would not be a aftermarket manifold. The fact of the matter is Ford did produce some of them for what ever reason regardless what your manuals say.