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440 Source Stealth Heads

Out of the box running stock cam, exhaust manifolds they should be a good improvement. Many will say to have them checked out which is a good idea, at least to make sure the valve job is correct and no sticking in the guides. If you have higher lift cam, the springs should be swapped out, retainers and locks changed, etc.

Check out the Edelbrock heads for a little more.
Always keep in mind that some of these heads have angle plugs, make sure that will work for your application. (Trust me you don't want to find out the hard way)
 
It depends on the situation. Don't get me wrong I like headers however you can make power with exhaust manifolds. They do not like a restrictive exhaust I can tell you that. Also, ditching the dp4b for a street single plane really woke things up. I do think that after a certain power level you have to dial in the camshaft specs to the combo (handicap exhaust due to restriction, minimize overlap to negate reversion) and the tuning window might narrow.

After my cam upgrade there will be a set of stealths in my future to replace the big valve 906's. It will be interesting to see how the tune up changes with a closed chamber. I think they are a fantastic head and am thankful someone made an OE appearing casting instead of the want to be billet look every other aftermarket head has.
Check out Nick's Guarge he has an episode on just this point, I think that the loss was 25hp VERY COOL I'm going to use stock manifolds (HP)
 
Might as well throw my 2 cents in I have Stock 440 source stealth heads (Changed the springs and retainers on the Valves) on my 512 (all 440 source innards as well) It all goes to the results you want. I only had one issue with when I got them I checked and the valves were not seating correctly so corrected that issue and they were good to go. I know that the limiting factor in my build is my heads. I have Headers. My Dyno results were at just over 500HP and 560FBT. With a 4 speed love it on the street. When I want more I will swap to some TF's. As for yours run it with manifolds when you want more put headers on. I think you would like the increase the stealth's would give you.
Just wondering who's running the 440 Source stealth heads, any issues with them ? What kind of power gain with the stock exhaust manifolds.
 
What cam made 500hp in a 512 with headers? A .509 should make 540 horse at those cubes.
 
I have about 300 miles on my stealth heads with new roller rockers. Just dropped the pan and found metal shavings in the bottom of the pan. Removed the valve covers and discovered there are clearance issues with the 8/8” pushrods that came with the kit and the pushrods for the intake valves are all badly scored. Going to call 440 source tomorrow to discuss possible causes and remedies
 
5/16" max pushrods without grinding the pushrod holes
 
I have about 300 miles on my stealth heads with new roller rockers. Just dropped the pan and found metal shavings in the bottom of the pan. Removed the valve covers and discovered there are clearance issues with the 8/8” pushrods that came with the kit and the pushrods for the intake valves are all badly scored. Going to call 440 source tomorrow to discuss possible causes and remedies

5/16" max pushrods without grinding the pushrod holes
I think there’s even a warning on that, might be on the website
 
I am using 0.083" wall 5/16" Smith brothers pushrods on the Stealth heads with the 1.6:1 ratio Harlan sharpe roller rockers.
Same thing with my friends big block with Edelbrock RPM heads. He had some off the shelf 3/8" pushrods that were rubbing the head and were actually a bit too long.
He bent a few pushrods, not sure how thick they were, but pretty thin? Been running the correct length 5/16" Smith Brothers pushrods for years now without issues.
 
For a street car is the extra 20HP worth the hassle of headers? Burnt wires, leaks etc. I would say not worth the aggravation. Now a track car is entirely different.
Yes! And especially so if you can get a set of headers off of someone that have very few miles on them and they didn't know how to make them seal or keep the wires from burning from being.....well, not knowing how to do that. lol I've purchased used and a couple of new and unused sets at 1/2 price and have been doing stuff like that most of my life. And what's the difference between a track car being so different in the aggravation department? None of my track cars were aggravating and so far none of my street cars were either. :)
 
I have about 300 miles on my stealth heads with new roller rockers. Just dropped the pan and found metal shavings in the bottom of the pan. Removed the valve covers and discovered there are clearance issues with the 8/8” pushrods that came with the kit and the pushrods for the intake valves are all badly scored. Going to call 440 source tomorrow to discuss possible causes and remedies
Someone didn't thoroughly read the directions, that's why they have problems!
 
A few comments if you stay with manifolds:
I assume the Scott Brown cam you have now is ground with a 112° lsa, as that is what Scott normally does. In my opinion, your 226/238 on a 112 lsa is a real nice exhaust manifold cam.

Be sure to have a direct and detailed conversation with Scott on the hyrdaulic roller upgrade. A 238°/246° even on a 112° lsa might be a little big, but I've never tried a hydraulic that size on a 440. And seat timing matters too. An aquaintance had his exhaust manifold car running 11.50s @ 116 with a smaller Scott Brown solid lifter cam, then switched to a 240° -ish hydraulic and is sucked power out of it, like 3 tenths and 3 mph. I think it hurt average power (verses peak power), but that is a guess.

In short, exhaust manifold motors are sensitive to cam timing and unforgiving with the wrong cam.
I had many conversations with Scott as it took 7.5 months to get my cam. Scott told me running stock exhaust manifolds is not an issue especially with the hydraulic roller cam he was grinding for me. Cam duration @.50 is 235/250. Scott likes the higher number on the exhaust when running the stock exhaust manifolds. Valve lift on the intake is .600 and .584 on exhaust. This is my current setup, 440 .03 over 440 source heads and I did have them checked out by one of the best head guys in my area and when I went to pick them up he told me he was very impressed by his findings, he said they checked out better than some of the more expensive heads which made me feel pretty good. Edelbrock performer RPM intake, Edelbrock 650 AVS 2 carb and a Pertronix 3 distributer setup, stock exhaust manifolds and a 4 speed with 354 dana. Never had the car to the track and probably won't but got to tell you she runs 100% better than she did.
 
i will have to try one, will it still pull in the upper rpms
I drove the car for a while with the carb as it was out of the box and decided to play around a bit. As is out of the box the acceleration light to light is very impressive. So I changed the metering rod springs to the pink spring, red is factory and it made a slight improvement, then I changed out the secondary jets from .098's to .104's and she pulls like crazy on the top end, that made a huge improvement. I'm extremely happy with the carb and 3 other buddies who were having issues with their Holleys switched to the 650 AVS 2 and are really happy with the performance.
 
I drove the car for a while with the carb as it was out of the box and decided to play around a bit. As is out of the box the acceleration light to light is very impressive. So I changed the metering rod springs to the pink spring, red is factory and it made a slight improvement, then I changed out the secondary jets from .098's to .104's and she pulls like crazy on the top end, that made a huge improvement. I'm extremely happy with the carb and 3 other buddies who were having issues with their Holleys switched to the 650 AVS 2 and are really happy with the performance.
I had many conversations with Scott as it took 7.5 months to get my cam. Scott told me running stock exhaust manifolds is not an issue especially with the hydraulic roller cam he was grinding for me. Cam duration @.50 is 235/250. Scott likes the higher number on the exhaust when running the stock exhaust manifolds. Valve lift on the intake is .600 and .584 on exhaust. This is my current setup, 440 .03 over 440 source heads and I did have them checked out by one of the best head guys in my area and when I went to pick them up he told me he was very impressed by his findings, he said they checked out better than some of the more expensive heads which made me feel pretty good. Edelbrock performer RPM intake, Edelbrock 650 AVS 2 carb and a Pertronix 3 distributer setup, stock exhaust manifolds and a 4 speed with 354 dana. Never had the car to the track and probably won't but got to tell you she runs 100% better than she did.
My Stealth heads are at my buddies place in Elbridge NY but he doesn’t do heads. Who checked out your heads? I may want him to check the ones that I’m using on my motor.
 
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My Stealth heads are at my buddit’s place in Elbridge NY but he doesn’t do heads. Who checked out your heads? I may want him to check the ones that I’m using on my motor.
The guys name is Jim Thomas 315 380 3884, he came highly recommended and I can see why he's very good at what he does. His shop is located in East Syracuse area. He's very reasonable on price. I plan on taking my original iron heads to him in the near future to have him clean them up but I don't have plans on putting them back on the stealth heads work very good.
 
The guys name is Jim Thomas 315 380 3884, he came highly recommended and I can see why he's very good at what he does. His shop is located in East Syracuse area. He's very reasonable on price. I plan on taking my original iron heads to him in the near future to have him clean them up but I don't have plans on putting them back on the stealth heads work very good.
Thank, That’s where my heads will be going to be checked. My buddy Ted has mentioned his name plenty of time.
 
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