A question about a 69 273

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Old Red Valiant

Old Red Valiant

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Hi Folks,
I bought a 69 273 motor with auto trans. I am replacing my /6 in my 66 Valiant.
The motor has been bored and the tranny is rebuilt. The engine will be assembled within the next week or two.
Thank God for the guys that still do these forms of art. The who did my transmission was incredible the way he just broke in down, while talking to me and 3 other techs that were asking him questions about their duties at the shop. He's been doing transmissions for over 30 years. The guy who bored my block is pushing 70 and was an instructor at a UTI school for a while. He retired and re-opened his machine shop. These guys are amazing, and I am forever thankful.
I was at the Good Guys show in Springfield yesterday and I was talking to the Edlebrock rep at their vending spot. I was inquiring about a intake for the 273 and he flat out said they don't make them anymore. I was bummed. But he said the 69 273 and 318 are the same. It that true?
Also does anyone have a used 4bbl intake for the 69 273?
 
You are lucky, the later 273 used the same intake bolt pattern as the later 318,340,360. I think it was 64 and 65 that had a few of the intake bolts at a different angle than the later ones. I think the intake that would work good for you is the LD4B edelbrock.
 
You are also very fortunate to run into some old school machinist that know our old Mopars in your neighborhood.
 
Sounds like you got it goin' on with your project. The 318 intakes should work fine. The difference in the 273/318 and the 340/360 intakes is the port size. Something to watch out for though is the 65 4 barrell intakes had a different bolt hole angle and smaller hole sizes. If you find a used Edelbrock, look for a LD4B which has the smaller 273/318 intake ports and the correct holes and hole angles. There was a Edelbrock Streetmaster 318 which should work also. I thing Offenhauser still makes one. Worth checking out. Welcome to the site. tmm
 
The larger port intake works just fine on the smaller port heads so there really isn't a reason for them to make both. I think Edelbrock Performer number is 2176 .
 
Actually, it's the "L"D4B, for late heads...the "D" 4B is for the early, wonky bolt angle and size heads. Eddy Performer and SP2P intakes will work as well

...and...


Yes...any intake that fits '69 318 will fit a '69 273, assuming it has the '67 and later heads.
 
65Val said:
Actually, it's the "L"D4B, for late heads...the "D" 4B is for the early, wonky bolt angle and size heads. Eddy Performer and SP2P intakes will work as well

...and...


Yes...any intake that fits '69 318 will fit a '69 273, assuming it has the '67 and later heads.
Click to expand...

Correction, 66 and later heads.
 
i was under the impression that the SP2P intake was intended for economy only, and not performance. i used to have a LD4B, I like it better than the regular performer intake on a 273. They do show up on ebay and for sale section here regularly...
 
I think you're right. They were a econo manifold. Like the Offy dual Port 360's were but either of these would be an improvement over a 2 barreli intake on a 8/1 compression 273. Hell, you might even get 20+ mpg on the highway. That's econo cruisin'. lol
 
toolmanmike said:
I think you're right. They were a econo manifold. Like the Offy dual Port 360's were but either of these would be an improvement over a 2 barreli intake on a 8/1 compression 273. Hell, you might even get 20+ mpg on the highway. That's econo cruisin'. lol
Click to expand...

SP2P was an economy manifold, but like you say, it was H*LLUVA lot better than the 2bbl setup!
 
check your block cast build date that will tell you for sure if its 69 or not,as long as the block was built from 66 up you can use the LD4B otherwise from 65 down D4B.Theres a vendor on the Aussie Ebay site selling one of the early type manifolds but has it listed for 273-360 which will only work with the early 273s unless the bolt holes have been re- drilled to except the later 66 heads.I have a LD4B in good condition with no porting done on the runners but the shipping cost from Australia to the US will hurt.
 
67 gt said:
check your block cast build date that will tell you for sure if its 69 or not,as long as the block was built from 66 up you can use the LD4B otherwise from 65 down D4B.
Click to expand...

The actual difference is the heads....the blocks are essentially the same, so check your heads' casting numbers to determine which intake to use. The early heads can be used on the later blocks, and vice-versa.
 
65Val said:
The actual difference is the heads....the blocks are essentially the same, so check your heads' casting numbers to determine which intake to use. The early heads can be used on the later blocks, and vice-versa.
Click to expand...

Yes. The heads are what will determine what manifolds will fit.

As stated above the 273 and 318 take the same manifold. The 273/318 heads are similiar to the 340/360 heads except the larger engines (340/360) have larger ports. The intakes will fit both 273/318/340/360, but the ports will be slightly larger with the 340/360 intake which will be a slight hit on efficiency. A 340/360 manifold will bolt up and work on a 273/318, but will have slightly larger ports.

The LD4B is a great manifold for the 318/273 as the ports will match correclty. When we bought my son's 71 Valiant 4 door a few years back, it came with dual exhaust and an Edelbrock performer intake and holley 4bbl. The Holley carb was in rough shape. We replaced the intake with a LD4B and Edelbrock 625 cfm carb and it ran MUCH BETTER. It ran strong off the line and mid range had nice pull to it, and no hesitation off the line. It's a great manifold for the street.

If you run a cam with 260° to 280° duration, the LD4b with a good Holley 600 vacuum secondary, or Carter/Edelbrock 625, and a nice set of 2 1/4" dual exhaust, you will have a nice running street/strip motor.
 
You can bolt on the 340/360 heads to a 273, but you would have to notch the bore for the larger valves to clear the bores. Then you could run the larger 340/360 intakes with ports to match the larger heads.

I think that you would be better off using the 273/318 heads with an LD4B intake.
 
65Val said:
The actual difference is the heads....the blocks are essentially the same, so check your heads' casting numbers to determine which intake to use. The early heads can be used on the later blocks, and vice-versa.
Click to expand...
Thanks 65 val on correcting that for me :D one to many wild Turkeys!!
 
krazykuda said:
You can bolt on the 340/360 heads to a 273, but you would have to notch the bore for the larger valves to clear the bores. Then you could run the larger 340/360 intakes with ports to match the larger heads.

I think that you would be better off using the 273/318 heads with an LD4B intake.
Click to expand...

Absolutely correct. One of the biggest downfalls with using 340/360 heads on a 273 is the larger combustion chambers with the bigger heads. You may end up with a 273 that has 7:1 compression. The small, closed, heart shaped chambers of the 273 are a very good design and very efficient. tmm
 
It all boils down to money. A 4 brl intake will require a 4 brl carb, throttle cable change, kick down linkage change, air cleaner change, and more. A cast iron dual plane 2 brl intake is just different enough from your OEM intake to provide better low end torque, more evenly dispersed fuel, and the EGR valve option.
To take full advantage of a 4 brl will require exhaust upgrade too. Hi-po manifolds or headers, mo money.
When I raise the hood at a cruise-in , those who don't know exactly what to look for will assume its all original.
The intake I would prefer to have for my Commando build is a Mopar Performance knock off of the LD4B. Reason being. it will take very little grinding and some red paint to make it look much like the Commandos cast iron single plane 4 brl intake.
Maybe I'll get lucky and trade a brand new Performer for the other.
Good luck 2 U 2.
 
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