Ya the stock 4v heads do flow pretty decent for old Iron heads. They just arnt the mosteffeientheads espesially for a street car that dosnt see 5500+rpm. A good set of Edelbrock heads would give you a lot more hp through out the low-midrange and add significant hp up top.

 

Mustang Monthly/Mustangs and Fast Fords/Mustang Illustrated/Vic Edelbrock Jr. has been saying this for years. Of course they've all been in bed together that long also. If you say something long enough, people will actually start believing you.

Out of curiousity, how many engines have run you with Cleveland 4V heads?

Dave

 

IMO Your setup has the potential to make more power if you so desire.

The first thing I thought when reading your post was "hmm iron heads,,, wait,, he said 351 Cleveland,".

IMO your basic engine, with the heads you have now,should be capable of 400 HP at the flywheel with relative ease... with the right cam, tune, and matched parts, if that is what you were looking for!

That said, I would not be disapointed in your numbers at all. I have to believe that the cam is pretty mild judging by the big torque number, and I think that if you ever decide you want some more push, a cam swap would go a long way to getting that 400 HP.

 

Stock Cleveland heads were great in their day, and flow better than other stock SBF heads, but plain and simple they are not even close to a modern well developed cylinder head. There is way, WAY more to a head making power than just how much it can flow. Port velocity, pocket design, chamber design, there are a lot of other factors that play into a head making good power. If that weren't true then why is it that modern high performance heads use much smaller ports with different port and chamber designs, and are making far more power? Clevelands don't flow all that great when compared to a modern cylinder head. Most deent 185cc port SBF heads will outflow 2V or 4V Cleveland heads by a pretty wide margin, and consider the port on a 4V is something like 230cc's. A modern performance head that has a 230cc port would make a 4V Cleveland head look like a paper weight. The air in the port needs velocity in order to fill the cylinder. What a head can do a dyno bench tells you very little about it's true ability to make power. Stock Cleveland heads are just 30 years behind technologically. You can't expect any engine part that's 30 year old technology to be competative with a modern part.

Your power numbers are fine for a street engine, and really about what you'd expect(depending on cam etc). But as the saying goes, you gotta pay to play. A good set of small port CHI's would most likely put the fwhp up to around 400. With the right setup a 350ish inch engine can make excellent power. That's why you see a lot of 347's that are running a 302 based head that are making 350-400 wheel horsepower and are driven regularly. Same size, better heads and roller cams. It really comes down to how much you want to spend.

 

do you have the port tounges? if not that might help your combo

 

Hey Dave, Ive never built a351 cleveland and I probably never will. I would perfer to build a windsor for performance but I can completely understand why you would build a cleveland if you had one, espesially if it was an origianl. 351c is a legend and there gettin rare. I agree with you that you cant believe all of what you read in the magazines.

1972 351c is a sweet ride though and 313hp with 375tq is a nice number for a reliable street car and you could always add a little bit of laughing gass for those ocations that you would like another 100hp.

Little off the subject was just lookin at a few crate engines Heres a nice windsor crate looked like a good deal for a turn key. There Ceveland version over $10000 though.

http://www.proformanceunlimited.com/...1_390carb.html

 

www.ausfordparts.com to make a lot more power out of your cleve

 

Thanks for the replies. Everybody pretty much seems that the numbers are good. So, I'm happy. And like Dave said, "It will snap your head back." Thats more of what I was looking for rather than a high top speed.

Again thanks and it looks like I have a good start point if I want to do some tinkering.

 

are they the early heads or later ones with only 28 degrees timing sounds like earlier ones if not stick some timing in it and see what it will do.should be able to put aleast 35to38 in it depending on your gas