Even though I can tune the HELL out of a Thermoquad, I prefer the Holley 4175 650 Vacuum secondacy carburetor. Somebody had one for sale on here recently too. Might still be here.
Offenhauser Dual Port Bore Diameter and Carburetor Clearance
- Thread starter Torqueflite
- Start date
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Even though I can tune the HELL out of a Thermoquad, I prefer the Holley 4175 650 Vacuum secondacy carburetor. Somebody had one for sale on here recently too. Might still be here.
Here it is. From a good member, too. And no, I don't get kickbacks. LOL That's almost a 600 dollar carburetor brand new.
[FOR SALE] - Holley 650 spreadbore
[FOR SALE] - Holley 650 spreadbore
Torqueflite
Well-Known Member
Thanks.
You're not going to do any better than that! What's this 318 going into? They're a great intake up to 4500 rpm on a towing rig.
Torqueflite
Well-Known Member
1927 Dodge roadster highboy build. It won't be towing anything but two people, 
but it will be a hot rod for street use that won't see over 5,500 rpm with the cam and will like power in the lower range. I've read on here that the Dual Port is a great intake for streetability on 273s/318s. If I come across a dual plane Equa-Flow for a good price, that's an option too.
but it will be a hot rod for street use that won't see over 5,500 rpm with the cam and will like power in the lower range. I've read on here that the Dual Port is a great intake for streetability on 273s/318s. If I come across a dual plane Equa-Flow for a good price, that's an option too.
gregcon
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Dual Port. Double Pumper. Dual Plane. DP this, DP that.
So back in the early 90's, I was living in Chicago. For you youngsters, this was before cell phones and DVD players and Netflix. People used wall phones, and VCR's.
I was looking for a good used record player, aka turntable, and one was advertised in the classified ads. It was located in Oak Park, which was a high-rent part of Chicago, so I figured it wouldn't be a some piece of caca. Worth checking out.
Sure enough, the lady selling it gave me directions to what was a very fancy house in a very fancy neighborhood. The thing is, she was a snooty git on the phone, and clearly looked down on me when I arrived. As if. So she tells me to wait in the front room, just inside the door, while she goes and gets the record player from further back in the house. So I'm standing there being careful not to touch anything that might break...and my eyes wander down the VCR that is sitting on the shelf under the TV. This was the sort of VCR that had the little door that covered the VCR tape port, but when there was a tape in the machine, the door only closed halfway, so as to allow the viewer to still see the tape.
There was a tape...inserted, shall we say.... in the VCR and the label read "Mandingo Double Penetration".
DP, indeed.
So back in the early 90's, I was living in Chicago. For you youngsters, this was before cell phones and DVD players and Netflix. People used wall phones, and VCR's.
I was looking for a good used record player, aka turntable, and one was advertised in the classified ads. It was located in Oak Park, which was a high-rent part of Chicago, so I figured it wouldn't be a some piece of caca. Worth checking out.
Sure enough, the lady selling it gave me directions to what was a very fancy house in a very fancy neighborhood. The thing is, she was a snooty git on the phone, and clearly looked down on me when I arrived. As if. So she tells me to wait in the front room, just inside the door, while she goes and gets the record player from further back in the house. So I'm standing there being careful not to touch anything that might break...and my eyes wander down the VCR that is sitting on the shelf under the TV. This was the sort of VCR that had the little door that covered the VCR tape port, but when there was a tape in the machine, the door only closed halfway, so as to allow the viewer to still see the tape.
There was a tape...inserted, shall we say.... in the VCR and the label read "Mandingo Double Penetration".
DP, indeed.
Thank you, I had forgotten about the that high boy being your project. Have you decided on which cam you're going to run?
If you want the best get any LD4B Edelbrock and forget everything else.
Everything I say is fully substantiated by my own opinion.
Everything I say is fully substantiated by my own opinion.
Or a Weiand stealth appears to be direct copy of an LD4B. The Holley Weiand site shows the ports at the flanges measure at 318 size.
I think I would stick with the Dual Port here. I don't believe any other intake, save for maybe the Air Gap will keep up with it from idle to 4500 RPM and that' where you're gonna be with a street cruiser like you have.
The thermoquad came out on International and other brands in about 68. That intake was modeled off of The Chevy Q jet. KimCom'on Rusty, don't hold back,lol
The TQ did not come out until 1971. Which implies that Offy didn't factor it in during the design stage...... of a 1970 manifold.
The small TQ has 1.375 bores, the larger IIRC is 1.4375. The AVS IIRC were a tad bigger.
A 600 Holley I think is 1.5625, a 650 is 1.6875
By the time you get an insulated gasket on there, you should have plenty of room
They're actually about 32 inches (265/75-160), so he's pulling around 2500 rpm at highway speed. He's going to check mileage next week after exhaust work. It does have the all time four wheel drive, but it's getting one of the conversion kits.
It just lacks the coil bracket stands. I found mine to be a PIA with horrible core shift and needed to grind on the outside of the intake to get the bolts started.
Thanks Rumble! Not the only instance I've heard of substandard casting from the Holley/Weiand consortium. Everything must be getting made in the Mr. Garbage division now.
For the OP, another honorable mention intake.
[FOR SALE] - Mopar Edelbrock Street Master 318 Aluminum Intake & Linkage
I haven't got to try one of these out but they're supposed to work really well to 4500 rpm. I wish someone would make a divored runner (air gap) version this intake with the same ports and runners but leave out the funnel restriction in the top of the plenum and terminate the runner dividers at the plenum corners. It would take a lot 318 (and gearing!) to make full use of it but I'm thinking it would work better than expected.
For the OP, another honorable mention intake.
[FOR SALE] - Mopar Edelbrock Street Master 318 Aluminum Intake & Linkage
I haven't got to try one of these out but they're supposed to work really well to 4500 rpm. I wish someone would make a divored runner (air gap) version this intake with the same ports and runners but leave out the funnel restriction in the top of the plenum and terminate the runner dividers at the plenum corners. It would take a lot 318 (and gearing!) to make full use of it but I'm thinking it would work better than expected.
I have used them. Good low end torque. Runs outta steam by 4000. That is a good deal. Kim
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