2v or 4v heads?

To start with, the engine in my '73 Mach-1 is a 4v Cleveland. If I keep the small block, I'm thinking of a 393c making around 450ish hp. This is a street only, daily driver. I'm thinking:

393C, 228/234 @ .050" hyd/roller cam, Edelbrock air gap intake, holley 750cfm, Sanderson shorty headers and 2 1/2" ,full length exhaust. Should I use the 4v headers or would that be to much head for that particular setup? I'm only asking because I've been told that the 4v heads are better suited for high RPMs. I'm planning on a tremec 5-speed with 3.50:1 gears.

I think it will run nicely with the 4V heads and that set up. Torque shouln't be a problem. You actually left out lift, but can I guess a .580 or so?

Thank you. I was thinking a little less. I'm not actually all that familiar with the cleveland motor. I grew up with Windsors. That cam on a 393W with AFR heads runs very nice and makes great power

How about having some Ford oriented camguy to have make custom camshaft for the engine. Somebody who knows the Cleveland 4V pros and cons. If it would be my engine, I might spend the few extra bucks and get the custom cam. Longer stroke will help the engine to breath for sure, but I could imagine having some extra overlap to get the best out of the big intake runners. Just a thought.

What sort of afr heads were on the windsor?

Remember, an engine is basically an air pump. By increasing the cubes you'll be increasing the air flow through it. Big valves and ports = air flow. The longer stroke will bump up your torque, so that shouldn't be an issue.

That makes sense. I'm not opposed to a custom cam at all.. I was planning on calling comp Cams anyways. That's just a general idea of the cam I was thinking of. The heads on my 393w are AFR-205's. I was just concerned that the 4v heads were to much for a "street motor"..

not at all, i think that is a myth caused by people trying to run them with 2.75 rear ends or 1050 carburetors or otherwise treating the engine like a chevy. That or people wanting top dollar for 2V heads

You are on the right track and should be pleased as long as your compression ratio is reasonable (Over 9.5 and under 11)

Great, thank you. As for compression, I was thinking of keeping it just below 10:1 (california fuel)..

Dude there are a great number of links posted here for indepth research and performance results on the Cleveland. You might enjoy checking it out, and will be surprised at what you read. There are no pat answers on 2v vs 4v...other than the open heads are always more prone to detonation than the quench heads. Best of luck

Will do..thanks

There are no pat answers on 2v vs 4v...

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I've given plenty of answers on 2v vs 4v....?

Ok, so a 73 open head 4v is always going to perform better than a 71 quench 2v? And a 4v without being stroked can still be better off the line than a 2v depending on rear gears...and the stall on the TC. Because Ford changed all the heads from 71-72-73 not to mention the aussies, and also the valve trains, it is fair to say their are no blanket response to what a 2v can do vs a 4v....unless you want to go to the flow bench. But i dont really think that is where this thread was going. But feel free to correct me.

Don't waste your time or money on 2v heads. The amount of effort and money it takes to get 400+ out of 2v heads is just not worth it. I was one of those guys that thought 2v heads where better for the street.:-/ Then I tried 4V heads in the same car. I will never go back. The amount of low end that the 2v head maybe,"maybe" has over the 4V does not out way the med to high range power the 4V head has.

Im guessing that when you switched from 2v to 4v you also did some valve work as well. And obviously you changed intake and exhaust manifolds. So again there is a lot of apples/oranges with Clevelands. One thing that isnt clear is what Caz is starting with? If you dont have ANY heads then get CHI 3v alum heads. If you already have 2v's are they quench? If you have 4v's are they open? Prefer to look original or happy with SS lines and a March serp belt system? I wouldnt spend money on 2v open heads. I tossed mine.

Don't waste your time or money on 2v heads. The amount of effort and money it takes to get 400+ out of 2v heads is just not worth it. I was one of those guys that thought 2v heads where better for the street.:-/ Then I tried 4V heads in the same car. I will never go back. The amount of low end that the 2v head maybe,"maybe" has over the 4V does not out way the med to high range power the 4V head has.

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As one of those guys who indeed wasted the time and money on the 2V heads, you just made me cry.

Im guessing that when you switched from 2v to 4v you also did some valve work as well. And obviously you changed intake and exhaust manifolds. So again there is a lot of apples/oranges with Clevelands. One thing that isnt clear is what Caz is starting with? If you dont have ANY heads then get CHI 3v alum heads. If you already have 2v's are they quench? If you have 4v's are they open? Prefer to look original or happy with SS lines and a March serp belt system? I wouldnt spend money on 2v open heads. I tossed mine.

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I purchased the car with the 4v heads, a cam 224/232 @ .050" and an edelbrock single plane intake. I believe it's a Victor. It also has 3.73:1 gears. The gears are nice but a little too low for the freeway. I was thinking of getting the edelbrock air gap intake and going with 3.25:1 gears. At least until I can swap to the manual transmission.

Don't waste your time or money on 2v heads. The amount of effort and money it takes to get 400+ out of 2v heads is just not worth it. I was one of those guys that thought 2v heads where better for the street.:-/ Then I tried 4V heads in the same car. I will never go back. The amount of low end that the 2v head maybe,"maybe" has over the 4V does not out way the med to high range power the 4V head has.

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As one of those guys who indeed wasted the time and money on the 2V heads, you just made me cry.

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I dont know if its a waste. I had 2v heads and had to work with what I had. i did put some money into them. All new valves, guides, cut for screw in studs, good bit of porting and port matching done. They seemed to flow pretty darn good for 2v heads. I ended up going with the afd 4v heads now and love them, but my 2v heads worked well. i was a little north of 400hp with the 2v. I sold them to theJ. Dont know if he got them on his car yet but i think he will be really happy with the setup that i sold him.

it all depends on application.

if you want a daily driver with traffic you go with 2V heads.

if you want a drag car your going with closed camber 4V heads.

open chamber 4V heads can be very problematic. ford reduced the compression ratio with the 4V the problem is engine builders get confused with the open or closed chamber heads,, so they build the bottem end of the cleveland like they are used to when they use performance heads or closed chamber heads, but then they stick a set of open chamber heads and you have major lean issues because under 1000 rpms the engine just will not run right.

but for drag if you are going super charger or turbo charger you want the lower compression to start to keep the engine from grenadeing.

so you have a dilemma: where you can't build a engine that is going to work all over you have to be specific.

the general rule is for a street car, when you want a 4 barrel go closed chamber, its traditional and most engine builders know how to deal with it, you can get good street and strip performance.

go open chamber and you open up to a list of issues depending on internal parts configuration. usually you end up with an engine with compression too low, because the builder didn't know to compensate for it. or you get an open chamber head somebody really messed with like they polished the chambers and reduced the compression even more, or they machined the valve stems and gave you a nightmare problem.

what happens is somebody sees a 4 on a cylinder head and they go Kid in a candy store thinking that found some holy BOSS 351 head but what they found was open chamber heads that they attempt to make fit in a closed chamber situation.

the reason the junk yards are full of open chamber 4V heads is because everyone junked them for closed chamber heads in 1972 and 1973 to get the power back after uncle sam stepped on the neck of auto makers and snapped there spines.

but there is nothing wrong with a good strong 2V motor they are spunkier on the low end.

4v's by nature are NASCAR motors, they want to hang around 5000 rpms all day long.

so they are crankier and lethargic under 3000rpms. Ford even Limited the rear end ratio factory options when you had a 4V to prevent people from complaining too much.

like others have said about using a 2.75:1 ratio and then having major problems. a combination like that meant somebody wanted to live in 2 different worlds they wanted performance and they wanted highway MPG... not going to happen.

i comes down to what you want. Do you want A/C and a nice cruiser? because i would point you at the small block 2V and a tall ratio.

do you just want burn outs and 1/4 mile cause your going either big block 460 or 4V with a short ratio.

and if your going un-natural aspiration then i would steer you at the open chamber heads and then you need to do some math.

there isn't that definitive you have to have one head over another, but there is a history of what works well.

you can have a very nice street car with 4V heads that are closed chamber as long as you pick from a selection of known parts that work well together.