440 Source Head Opinions?

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Hallzy said:
I'm skeptical on that I'm not sure on the 240s flow numbers but

How long is that 383 gonna live? My point was for a budget they aren't bad at all and can be made to work pretty good. Honestly I think if I can get mine to even hook at the level it's at I will be a happy guy.
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Hey I understand why guys would pick one or the other based on cost or performance, I was just saying that your estimate on the difference in power potential is just incorrect. Now I also realize you don’t want to spend the money so you need to justify your position. I put up what I know not based on opinion but on fact because there might be someone that takes your position as fact and not conger that it is.
I personally don’t care what head anyone uses but I am interested in how well they work…
 
Oldiron440 said:
Hey I understand why guys would pick one or the other based on cost or performance, I was just saying that your estimate on the difference in power potential is just incorrect. Now I also realize you don’t want to spend the money so you need to justify your position. I put up what I know not based on opinion but on fact because there might be someone that takes your position as fact and not conger that it is.
I personally don’t care what head anyone uses but I am interested in how well they work…
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That's fair the reason why I said I was skeptical is after porting my budget heads were right at 298 cfm @ .500
312 or something at .700
I'm just not sure if the performance increase would be as much as you are saying, however there are so many other factors at play here my compression is only 11:1 on pump gas I'm running smallish headers etc.. I don't think in obtaining the numbers you say that the heads alone can be attributed to being the sole reason for achieving that level with the 240s considering they only flow 15 or 20 cfm more than what I have
 
Oldiron440 said:
20 or 30 hp more you can tell yourself that but it’s more like a 100 hp more with TF 240. Ive seen 760hp from a 4.15 stroke 383 with out of the box TFs. A hundred or more hp for $1200, thats a deal!
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Isn't the TF 240 a CNC ported head? I'd sure hope it would flow more than a cast port head.
 
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ultimatejay said:
I posted an in depth video of guy who specializes in cylinder heads and porting and he gave his opinion. So if your butt hurts because these heads are not super super great and then I dont know what to tell you. If you want a cheap cylinder head that flows like crap then this head is just for you. In my opinion I would just buy some stock heads and get a good valvejob and porting done to them then buying these.
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And you'd probably have more money in a 50 year old iron head than you would in a pair of Stealth heads!
 
Oldiron440 said:
20 or 30 hp more you can tell yourself that but it’s more like a 100 hp more with TF 240. Ive seen 760hp from a 4.15 stroke 383 with out of the box TFs. A hundred or more hp for $1200, thats a deal!
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That was, what...a high-squeeze drag motor running avgas or race fuel (or alky), probably with a tunnel ram or a high-rise intake and a Dominator, cam that idles at 1700rpm, and big-tube open headers?

Hallzy said:
I'm skeptical on that I'm not sure on the 240s flow numbers but

How long is that 383 gonna live? My point was for a budget they aren't bad at all and can be made to work pretty good. Honestly I think if I can get mine to even hook at the level it's at I will be a happy guy.
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I can't imagine that was in any way a street engine.
 
Jarlaxle said:
That was, what...a high-squeeze drag motor running avgas or race fuel (or alky), probably with a tunnel ram or a high-rise intake and a Dominator, cam that idles at 1700rpm, and big-tube open headers?



I can't imagine that was in any way a street engine.
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E85 was the fuel with a 950 Holley that had a clean idle around 900 rpm and 1 7/8” step headers but it doesn’t matter the heads still made the power, you don’t get that for $850 with a pair of china’s **** heads….
 
ultimatejay said:
Yeah, it was all done by the stock combustion chamber flowing stealth heads. SMH
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You do realize they flow more than stock heads, don't you? The chamber is based off the stock configuration, not is the stock configuration.

Like I said, I can't wait to shave 4 or 5 seconds off my time slips!
 
Let me put it this way since you guys can't comprehend it. You're losing more time off your et with the weight savings vs the power gain these heads are giving over stock. What are we talking 10hp? SMH Has anyone given dyno proof of the power gains from just a bolt on nothing changed good stock heads and then bolt an untouched stealth heads on? I doubt it, most people change cam and intake and port the stealth heads and then claim all this big power gains.
 
ultimatejay said:
Let me put it this way since you guys can't comprehend it. You're losing more time off your et with the weight savings vs the power gain these heads are giving over stock. What are we talking 10hp? SMH Has anyone given dyno proof of the power gains from just a bolt on nothing changed good stock heads and then bolt an untouched stealth heads on? I doubt it, most people change cam and intake and port the stealth heads and then claim all this big power gains.
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I wish I had my old flow sheets still but I know stock 440source heads flowed around 267cfm max. Now you stuck the word good stock heads so I can’t say you are right or wrong because maxed out big block heads can be made to flow in the 300cfm area in the right hands. Some do, most don’t. I never really played with stock heads but have a set of stock ported heads that ran 9.82 back on the 1980’s in my 74 duster. So it can be done but I know how easy 440source heads jump up to 305cfm because I did it easily way before I knew what I know now. What would really be a nice addition to this post would be flow numbers from .300-.550 with both heads. That would tell the whole story. I can’t help with that but we have a couple of members that could. Step on in guys. The waters warm.
 
Stealth heads with the seats recut and a nice bowl blend with flow right about [email protected] lift.

Most home ported stock heads(especially 906’s and 915’s) I’ve tested are typically in the 250 and less range.

The [email protected] is a little more than these flowed:

DBC9A66D-8839-4B9D-9D69-4ADE493AA654.jpeg


35D64386-7BC4-4B95-B41B-24F9294A6D1B.jpeg


On my bench an ootb TF240 flows right about 316/[email protected], and 320/[email protected] lift.
I’ve tested about a dozen of them, they’ve all been within a few cfm.
 
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PRH said:
Stealth heads with the seats recut and a nice bowl blend with flow right about [email protected] lift.

Most home ported stock heads(especially 906’s and 915’s) I’ve tested are typically in the 250 and less range.

The [email protected] is a little more than these flowed:

View attachment 1715901405

View attachment 1715901406

On my bench an ootb TF240 flows right about 316/[email protected], and 320/[email protected] lift.
I’ve tested about a dozen of them, they’ve all been within a few cfm.
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I was hoping you would post up the numbers for these guys. I figured you and Brian would have that info.
 
Reading through this.... I'll take one for the team. IF you have new Stealth heads in the box, I'll go ahead and give you some free HP and drop your ET by trading you even up for my factory 452 heads on my 440. Even up! I'll take the loss.
 
fishmens67 said:
Jim/IQ52 has very informative thread on the Stealth head OOTB vs prepped flow #'s.
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It’s not my post and I honestly didn’t have much to add but I knew some of these guys had both heads, stock, ported stock, stock stealth heads and ported stealth heads for a fair comparison
 
PRH gave a great example of the stealth heads I just did. The valves were sticking out off of the seat. It was close to .080 that I ground to get the seats correct but other than that the spring installed heights were really close across on both heads. Good head for the price.
 
Oldiron440 said:
E85 was the fuel with a 950 Holley that had a clean idle around 900 rpm and 1 7/8” step headers but it doesn’t matter the heads still made the power, you don’t get that for $850 with a pair of china’s **** heads….
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With, what...13:1 squeeze? Maybe more?

And, of course...all else being equal, alky makes more power than gas.
 
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