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What are the advantages and disadvantages of using the 4V heads vs the 2V heads on the street. I am running a 351C with a lunati hydralic cam 280 290 duration and 550 556 lift, a 1800 stall, holley 650 dual line and holley street dominator (single plenum) intake. Has anyone used this combo or have any idea how much power I can expect.

Thanks
Mad Cat
 

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dont spend your money on the 4V heads for the street. You'll get better performance with the 2V heads, if your running a 4 speed, then go for the 4V heads. Spend the extra money on the 2V ones by porting and gasket matching and converting to adjustable rockers. You'll notice a big improvement by doing that and still run pump gas without detonation. :D
your convertor isnt good enough for 4V heads, you'll need around 2800-3000 stall for 4V heads to work to there potential.

Rick
 

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If you want to change heads go for the aussies.
 

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The 4V heads don't have very good port velocity for the street. Which makes them cause an unnaturally rich condition at idle on an engine with a big cam.
The 2V heads are good with what dark said before. Screw in studs and roller rockers are good additions.
Aussie heads are worth the money if you get a good deal. Other options are the 351 CJ heads. If you can find them.
And, of course, if you have the jack you can opt for some nascar parts from the 80's when they ran the cleveland. Lots of shops are liquidating them now.
but then, we were talking street car too.
As for your power potential, I had a Boss 351 solid cammed engine with 2v heads and flat top pistons. 1800 converter. 3.5 detroit locker. street tires, mufflers, full interior.
I ran [email protected] mph uncorrected at Bristol in the summer heat at 2:30 or so. With lots of wheel spin at 1-2 gear change.
Post some more info on your combo. Maybe someone can plug the values into desktop dyno for you.
 

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Aussie heads best of both worlds.
Quench chambers, like the '70 M-code.
Big valves, (ditto).
Smaller 2v ports for velocity.
Keep an eye on compression, though...

Love mine.
 

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How about port plates on 4v heads. Would it make them more streetable?
 

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bowl, it would help the flow, but your still up in compression. Ive heard that they dont seal worth of $hit though.
 

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Edlebrock makes a great perfomance package. Heads, intake, carb, cam. look on the net and get a free catalog.
 

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Dude, I wish edelbrock would make some aluminum cleveland heads!

I've heard the same about the port plates. They suck.

However, you could go the route of filling the intake port floors with weld and then grinding them back out to the best flow potential and velocity. But then, you'd need a welder, die grinder, and a flowbench. But, it works pretty well. From what I hear, that is. You can also use epoxy, if you don't want to weld...:alien:
 

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I'll stick with the 4v heads like they are, if I dont like the way they perform I have a set of 2v heads on the parts car. if they are good Ill take them to "machine head" in Stafford.
Thanks for the port plate info.

rich
 
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