Port-o-sonic or Holley Street Dominator?

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75slant6

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Looking for opinions/recommendation on which intake to pick up.

Engine info: mild 5.9 magnum with stock pistons, .218/.224 cam, speedmaster aluminum heads (not sure yet if I’m gonna get them ported or not, need to get some quotes). Plan would be to add injector bungs to whatever intake I run and running the factory magnum EFI on it.

Gearing info: I’m running 2.76 gears BUT I installed an AX-15 5 speed that has 3.83-2.33-1.44-1.00-.79 ratios which essentially makes the rpm in the first 3 gears almost identical to a 904 with 4.10 gears. (Comparison picture below)

The car is 99.9% street driven, I do autox and drag race it once a year at MoParty.

If any more info is needed, I’ll be happy to answer any questions.

576AC866-CBB1-4343-B8CB-129330513843.jpeg
 
I also thought about using a performer rpm and an air gap, but figured the single planes are going to be easier to install the injector bungs in the runners.
I also currently am running a China-gap knockoff intake and originally my plan was to just use that intake, but I’ve read multiple reports of the knockoff giving up 20-40hp to the Edelbrock Air-gap, depending on the engine configuration.

One advantage I thought of, between either air-gap intake vs the single planes is the cooler intake charge and since it’d be efi, there wouldn’t be any cold weather drivability issues in the winter.

Pro’s of the single planes over the air-gaps is obviously the runners being same height for bungs and also hood clearance.

Pro’s of the China-gap, I have it. Lol
 
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I would be interested in how the AX15 fit. Bellhousing,clutch, clearance mods . What did you get the tranny from? :popcorn:
 
Wow, both intakes are not to good for the build. The cam is way small for what I’d run the Offy, given the choice.

Holley did t make a “Street Master” but Edelbrock did.
Holley made the “Street Dominator.” Which I’m not really fond of.
 
I would be interested in how the AX15 fit. Bellhousing,clutch, clearance mods . What did you get the tranny from? :popcorn:
My tunnel and upper crossmember were torched out by a previous owner so I ended up just installing the transmission and building a new tunnel around it. Transmission came out of a 98 Dakota, flywheel from a 98 Ram with a 5.9, clutch and pressure plate are all factory 98 Dakota parts, clutch master/slave setup is from a round nose s-10, reused the factory clutch pedal.
 
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FWIW, it's my understanding that the Port-O-Sonic is more of a performance intake (i.e., works better at higher rpm) than the Streetmaster. I think I remember that back in the nineties, Ed Hamburger recommended the Port-O-Sonic as one of the best performing SBM intakes available.

Edit, just noticed that the OP referred to the Streetmaster as a Holley intake. As Rumblefish notes, the Streetmaster is an Edelbrock intake. The big block Holley Street Dominator is supposed to be really good, but the small block Street Dominator, as I remember from the one that came into my possession a while back for some reason, has 318 sized runners.

I did run a Port-O-Sonic on my stepson's 340 Duster that had a fairly mild cam. Worked well, I thought.
 
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Wow, both intakes are not to good for the build. The cam is way small for what I’d run the Offy, given the choice.

Holley did t make a “Street Master” but Edelbrock did.
Holley made the “Street Dominator.” Which I’m not really fond of.
Oops. Street Dominator is what I had in mind. I’m also open to other suggestions.
 
Oops. Street Dominator is what I had in mind. I’m also open to other suggestions.
I change my choice… the smaller runners of the Holley are probably more favorable for the small cam.
 
That’d be ideal, but I’m not gonna pay $700+ for an intake. I’ll stay carbureted before I do that.
You'll be close to that by the time you get bungs machined and welded into an existing manifold and have to get custom fuel rails made up- and still be saddled with a "compromise" manifold. Then there's the throttle body adapter and other miscellaneous hardware that's included in the Hughes kit (which also accepts stock fuel rails). Not to mention that the LA manifolds that you mention won't work with the Magnum serpentine drive, requiring you to swap to the LA TC cover, water pump and v-belt drive. It adds up fast.
Do the Speedmaster heads you're looking at take LA or Magnum intakes?
 
Transmission came out of a 98 Dakota, flywheel, clutch and pressure plate are all factory 98 Dakota parts
Just a heads up- don't forget to have your flywheel rebalanced for a 5.9- the V6 and 5.2 Magnum that the AX15 came behind are both internally balanced; the 5.9 is external. The V6 version of the flywheel also will not have the correct number of crank position sensor pickups to run your factory EFI on a V8.
 
Holley Streetmaster? Can I assume you mean the Street Dominator? Or do you mean the Edelbrock Streetmaster? The Street Dominator isn't bad, the Streetmaster is.

The old "single plane v. dual plane" discussion is far less important where MPFI is concerned, unless you're really interested port speed for bottom-end grunt. The Street Dominator has smallish, slightly-longer ports than the Offy, or say an Edebrock Victor or Strip Dominator. I think it would be good choice for an MPFI intake for that reason, along with relatively low overall height and ease of consistent injector height... although the same goes for the Port-O-Sonic in terms of the latter two. The Dominator would be more torque-oriented, but the difference would likiley be virtually negligible.

If the other choice is the Eddy Streetmaster, it's Offy hands down. The only aftermarket intake arguably worse than the Streetmaster is Edelbrock's SP2P. Either might work well on a mild 273 or 318, but are pretty restrictive for the 340/360 engines.

Just a word of caution: The factory ECM can't account for increases in airflow through the engine such as hotter cams, ported heads, etc. It sounds like you're staying pretty mild on the cam, but it's worth mentioning. A couple of acquaintances who believed that "the oxygen sensor will figure it out" got expensive lessons regarding the limitations of speed-density EFI.
 
Just a heads up- don't forget to have your flywheel rebalanced for a 5.9- the V6 and 5.2 Magnum that the AX15 came behind are both internally balanced; the 5.9 is external. The V6 version of the flywheel also will not have the correct number of crank position sensor pickups to run your factory EFI on a V8.
Or buy a manual flywheel for a 5.9 from a 2500 truck. That's what I did when I put a 5.9 in my (formerly) 5.2 powered 5 speed truck.
 
I say Holley Street Dominator, I had one on a SBC, on the street, pulled from idle to 6000.
I also had a Port -o- sonic single plane that didn't have the bottom end of the Holley, but pulled very hard from 3500-6000
 
You'll be close to that by the time you get bungs machined and welded into an existing manifold and have to get custom fuel rails made up- and still be saddled with a "compromise" manifold. Then there's the throttle body adapter and other miscellaneous hardware that's included in the Hughes kit (which also accepts stock fuel rails). Not to mention that the LA manifolds that you mention won't work with the Magnum serpentine drive, requiring you to swap to the LA TC cover, water pump and v-belt drive. It adds up fast.
Do the Speedmaster heads you're looking at take LA or Magnum intakes?
You do make good points there, I’ll definitely do some number crunching before it all happens. That said, call me weird, but one draw to using a different intake over the Hughes one is the challenge of figuring everything out to make it work. I do plan to use the factory magnum rails, regardless what manifold I use, and probably use a 4 barrel throttle body if I use a modified intake.
Also, if the Hughes intake, adapter and tb are even a 1/4” higher than my current China-gap and edelbrock carb are, I won’t be able to run it. My engine is raised 3/4-1” and even with a 2” drop base my air cleaner lid JUST touches the underside of my hood.
Oh, I completely forgot, my speedmaster heads are la intake pattern.
 
Just a heads up- don't forget to have your flywheel rebalanced for a 5.9- the V6 and 5.2 Magnum that the AX15 came behind are both internally balanced; the 5.9 is external. The V6 version of the flywheel also will not have the correct number of crank position sensor pickups to run your factory EFI on a V8.

Or buy a manual flywheel for a 5.9 from a 2500 truck. That's what I did when I put a 5.9 in my (formerly) 5.2 powered 5 speed truck.
Oh yeah, should change that in my earlier post. I used a flywheel from a 98 5.9 Ram, not a Dakota.
 
I would use the Hol St Dom intake. The Port O Sonic is a race intake. The St Dom is a street intake. The original rpm range quoted for the HSD was 0-5500 rpm, though I have seen this changed recently to 0-6000......for the same intake. I have used the HSD on a few different brand engines & all performed well & as advertised. It would be a good choice with the cam you have chosen.
 
You'll be close to that by the time you get bungs machined and welded into an existing manifold and have to get custom fuel rails made up- and still be saddled with a "compromise" manifold. Then there's the throttle body adapter and other miscellaneous hardware that's included in the Hughes kit (which also accepts stock fuel rails). Not to mention that the LA manifolds that you mention won't work with the Magnum serpentine drive, requiring you to swap to the LA TC cover, water pump and v-belt drive. It adds up fast.
Do the Speedmaster heads you're looking at take LA or Magnum intakes?
Sounds like you've been there!
 
Between the two, the Port O Sonic will act way more like a single plane, while the Street Dominator really gives up nothing down low. I'd use the Street Dominator with your combo, just given those two choices.
 
Sounds like you've been there!
Yeah, years ago when there weren't many choices. Was trying to get a lower profile manifold and keep everything under the hood; like the OP just mentioned. The stock kegger and the old Crosswind 2bbl. manifold would JUST clear the hood with a drop base air cleaner; since the factory throttle body is nowhere near as tall as a 4 bbl., but I wanted more room for a bit taller air cleaner. Ended up taking between 1/2-3/4" off the top of the Crosswind, there's plenty of meat up there. It was REALLY pricey to convert a manifold at the time (bung install, fuel rails, mounting lugs on the manifold for the fuel rails, then drilling the heads for the LA pattern... you get my drift. Plus the fact that I'm a cheap bastard!).
1666822153940.png
 
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I also thought about using a performer rpm and an air gap, but figured the single planes are going to be easier to install the injector bungs in the runners.
I also currently am running a China-gap knockoff intake and originally my plan was to just use that intake, but I’ve read multiple reports of the knockoff giving up 20-40hp to the Edelbrock Air-gap, depending on the engine configuration.

One advantage I thought of, between either air-gap intake vs the single planes is the cooler intake charge and since it’d be efi, there wouldn’t be any cold weather drivability issues in the winter.

Pro’s of the single planes over the air-gaps is obviously the runners being same height for bungs and also hood clearance.

Pro’s of the China-gap, I have it. Lol

I wouldn’t go to war with the thought the air gap is 20- 40 horse better than the crosswinds type.
that’s insane.
I owned an enginemasters entry…477 horse stock stroke 318, iron magnum RT heads little over 10 to 1 compression.
it sported a trick hp 950 carb and the Chinese knockoff air gap.
I ran it detuned( much smaller cam) still went mid 11’s at 115+ in a 3400 pound car. 230-238@50
there are intakes that might show as big of a change/ gain as you are talking about.. but airgap to airgap on a mild combo like you have…I would be shocked it the difference( if any) was 5-8 horse.
the enginemasters guys( mighty sharp) must have agreed with me
people say wild stuff like that, lol

Iron-Headed Mopar 318 Magnum Engine- Popular Hot Rodding Magazine
 
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That’s true. The difference between the two intakes is small on low power builds. When you twist the screws to the intake and push the power levels way up, that’s where you find the difference.

I used the chink knock off on my sons ‘91 4X4 dodge with Edelbrock heads and carb. The cam is the small thumper. I’m not taxing the intakes potential. If I have the cam another 30* in duration, ported heads, etc….. I’m sure we would see something.
 
I definitely appreciate everyone’s input and advice! I picked up the street dominator off eBay tonight for $225. Once I get the engine put together and installed, I think for the fun/knowledge/experience of it, I’ll run my current China-gap intake and the SD back to back (with a carburetor) and see how those two intakes compare. Who knows, that may show that I should put bungs in the c-g and use the SD in my Scamp later on. Unfortunately I’m just in the early stages (only a dirt pad so far) of building my shop at our new place, so it’ll be awhile before this all comes to fruition.
 
I definitely appreciate everyone’s input and advice! I picked up the street dominator off eBay tonight for $225. Once I get the engine put together and installed, I think for the fun/knowledge/experience of it, I’ll run my current China-gap intake and the SD back to back (with a carburetor) and see how those two intakes compare. Who knows, that may show that I should put bungs in the c-g and use the SD in my Scamp later on. Unfortunately I’m just in the early stages (only a dirt pad so far) of building my shop at our new place, so it’ll be awhile before this all comes to fruition.
I think that's the smarter choice of the two for your build. The Port O Sonic will blast it past 6K, but I don't think that's where you're going. I actually believe up to about 4500 or possibly more, the Street Dominator might have the advantage. Certainly I believe on a mild build like yours. I have an almost NOS Port O Sonic for a 351 Cleveland 4V engine and that thing is one hellified lookin intake. I think Offenhauser advertised it to pull past 7500 and I'm sure it will.
 
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