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There are many aluminum heads available for the 351C. But before discussing heads, you need to decide on a few parameters first.

What powerband will you be building into your engine? For instance, 2000 to 6000 rpm, is a very good street powerband.

What type of induction (air & fuel system) do you think you would like to set on top of your engine? A 2000 to 6000 rpm powerband in a carbureted engine works better with a 2 plane, divided plenum intake manifold. On the other hand a 3000 to 7000 rpm powerband in a carbureted engine is a good match for a single plane intake mainfold.

Do you mind if the induction system pokes through the engine screen & is visible in your rear view mirror, or would you prefer to keep the induction system below the engine screen?

Will you be building an engine from the ground up, so that piston selection can be made based on the heads you select, or are you bolting these heads on top of an existing 351C with standard Cleveland pistons?

What is the displacement of your engine, stock or stroked?

Just to be thorough, are you assembling these heads on a 351C block, or a Windsor block?

The final consideration is what exhaust systems are available off the shelf. To my knoweldge there are exhaust systems for 351C 2V heads, 351C 4V heads and the high port Motorsport heads (A3, B351 & C302). There also headers available for Windsor heads on a 9.5" deck height Windsor block. Luckily, this selection will allow many choices in cylinder heads.

Making power isn't a matter of bolting on parts randomly, but assembling parts that will work together as a system.

So if you can answer the first 6 questions, everyone on the BB will be able to provide a better informed response.

And you thought you asked a simple question, huh?

regards, George

I'll answer your question about the oem Cleveland heads first. The difference between 2V & 4V heads is the size of the ports. The 2V ports are very big, compared to those in the heads of competing American engines (small block Chevy, small block Mopar). The 4V ports are enormous. Ford was in a bigger is better mode in the '60s. As racing has progressed, the size of the ports in the Cleveland racing heads grew smaller & smaller, as the racing community learned that port shape & gas velocity were more important than size alone. The basic design of the Cleveland cylinder head is excellent however & was copied by Chevy for their NASCAR engines in the '90s, and my understanding is the latest generation Corvette has cylinder heads that incorporate features of the Cleveland cylinder head design.

Cast iron Cleveland cylinder heads manufactured by Ford come in 5 flavors, the variations being the size of the ports, the size of the valves and the shape & size of the combustion chamber. The '70 - '71 351C4V had big port heads, with big valves and "closed" combustion chambers. The '72 351 CJ (cobra jet) had big ports, big valves and "open" combustion chambers. The '73 - '74 351C 4V had big ports, smaller valves and open combustion chambers. The 351C 2V engine, not used in the Pantera, had small ports, smaller valves and open combustion chambers. Over in Australia, a smaller displacement Cleveland engine was in production, a 302 cubic inch Cleveland (302C). This engine had small ports, smaller valves BUT closed combustion chambers.

The heads with closed combustion chambers raise the compression of the engine about 1 point, and with proper machining of the block, can increase bhp by creating a tight space between the piston & flat surfaces of the head referred to as "squish". As the engine comes from Ford, the space between the piston & head is too great to realize the benefits of "squish".

The subject of cylinder heads is a big one, I've not even scratched the surface. For now let me make a recommendation for you. PI Motorsports sells aluminum cylinder heads manufactured by an Australian company called Cylinder Head Innovations (CHI). Currently they sell a head called the 3V head, but CHI is just introducing a new 2V head. The CHI 2V head, with the new Edelbrock RPM air gap intake manifold, a 750 cfm Holley carburetor, a Competition Cams XE274H camshaft will build you a great street motor, lots of power, excellent throttle response. You can employ your existing exhaust manifolds, and the induction system will be low enough to sit under the engine screen. The intake manifold has the independent runner look of the high rise manifolds. Using the stock exhaust manifolds will prevent this combination from making all the power its capable of, but guessing conservatively, this set up should be good for 75 additional horsepower.

Please be aware that installing new or rebuilt cylinder heads onto a short block with lots of miles on it will most likely result in excessive oil burning.

Last edited by George P
Power over what RPM?

between 2000 & 6000 rpm with stock exhaust manifolds...NADA.

However the 3V head has a higher port, requiring usage of a dedicated CHI intake, or a 2V intake with a CHI spacer, which raises the induction system 0.4". The CHI intake is quite high and your induction system will have to poke through the engine screen. It is a single plane intake and not as good a match with the cam I've recommended. The 3V heads, CHI intake, a hotter cam (3000 rpm to 7000 rpm)would make a good match, but better exhaust manifolds will be a must, or you're wasting your money. You would also be wasting your money to bolt these parts onto a short block with alot of miles on it. This combination has tremendous potential to make bhp, but not with a marginal ring seal and not without extensive cylinder block work. This combination would also stress the lower end of a high mileage engine to the point something will break.

The Edelbrock RPM air gap manifold will be tight as is, with a 0.4" spacer it may also require a hole in the engine screen, a lower manifold such as the Edelbrock performer will not be as good a match with the parts I've recommended, hence my recommendation. Make sense? Are you getting a feel for the "system" approach to building an engine.

The 2V heads will make a good foundation for you to use now, and make more power with later. Rebuild the engine, install a stroker crankshaft & a hydraulic roller cam and those heads will provide you upwards of 500 bhp. I think CHI advertises they'll support over 600 bhp. If you want to bolt up a wild induction system to them, a Parker 2V Funnel Web manifold would bolt right up. Trick Flow is supposed to be working on a fuel injection manifold for 2V heads.

Seems to me to be a good way to meet your needs now & in the future. Heck the more I write about it, the more I'm thinking I "need" a set of those heads.

Originally posted by MARLIN JACK:
Panhe, I can't speak for your '74L, but My '74L #5723 came stock with 4V heads (Open Chambered), and 4 Bolt mains. Yes! It did have dished pistons making a compression ratio of 8.0:1 The New 'Boss 358' is a totally different animal. Regards,
I am having a 400 built using the CHI heads. I am in the process of shipping them right now to the engine builder. I was going to assemble the engine myself but he has a dyno and is pumped about the project. I am looking forward to seeing the engine dynoed by itself then in the car. I'll provide some info when I can.

the XE274H is a flat tappet hydraulic cam with the agressive ramps of the Comp Cams Xtreme Energy (XE) line of camshafts. It has a rated power band of 2000 to 6000 rpm. I have that one memorized (sometimes) because of the power band. The XE cams feature higher lift than Comp Cam's other lines of flat tappet hydraulic cams, the Cleveland responds very well to higher lifts, it gets the velocity up in the big ports of the Cleveland cylinder heads. In Comp Cams notes on that camshaft they make special mention that this cam has excellent throttle response, a comment they fail to make regarding any other Cleveland camshaft.

Drawbacks? Those aggressive cam lobe ramps make more tappet noise than other, less aggressive camshafts.

I am not familiar with the cam you mentioned, apparently you got the number from somebody else, but you fail to mention who. I do not like being put into a position where my advice is being pitted against the advice of somebody else, especialy when I am not informed whos advice I am "competing" with. I am always willing to step aside for someone of greater authority.

Please don't believe what you are told on eBay. Well except for Marlin, he's selling his pilot bushings there. Smiler Oh, and Roland has some cool signs for sale, asking more than I can afford though. Wink Everyone else will say anything to sell product and make money. They aren't interested in you getting the best parts for your needs.

What I get out of this is personal fulfillment in having helped somebody. If I fail to help you, I don't get paid! Frowner

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