'67 Cuda 273 2bbl to 4bbl upgrade?

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Shingar

Shingar

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Brand new to the forums.
Just bought my old high school car back after selling her over 25 years ago.
1967 Barracuda convertible. Man have I missed her!

Still has the 273 2bbl in. I would like to upgrade to a 4bbl. I have searched parts but cannot find an intake manifold that says it is compatible with this 1967 273.

Not sure it makes a difference.....but car has power steering/brakes and A/C.

Any suggestions on where I can find a manifold to fit?

Also...open to suggestions on a compatible 4bbl carb.
 
Any 318 four barrel intake will fit, including the original 273 4 barrel intake. 273's have the small port heads like the 318. I'd suggest the 500 cfm Edelbrock. If you upgrading other things like cam and valve springs, you can go bigger. New Intakes like the Edelbrock Performer should work quite well for what you want to do. It will also accept a Thermoquad or Quadrajet carb, so you will not be limited to carb size or style down the road. This assumes you have the stock 67 273. It is best to get a 340 throttle cable bracket and kickdown linkage, since the 2 barrel kickdown will not be long enough.
 
66FS,

Correct > An Edelbrock Performer #2176 or Weiand Action-Plus #8007 will do the
trick for a 'basic' 4-Barrel upgrade.

Both Aluminum Intake Manifolds will 'match up' with the stock 273 Cylinder Heads.

Weiand Action=-Plus #8007

WND-8007_AF.jpg
 
The intake issue is not present on your year car/engine. The first two years of the 273 engine are the issue with intakes.

The above mentioned intakes are what your after. Carb wise, that 500cfm Edelbrock is a great idea or a sub 600 CFM Holley. 600 CFM is the max I'd go and not so willingly. If you can not source the original type linkage for the carb/trans, look to Lokar or equal for cables. There easy to install.
 
Unless you plan to improve exhaust flow, a bunch of aftermarket intake and carb is a waste of coin. The changes in linages, air cleaner, etc.. is more headache that its worth for sure.
If you can find a later model 318... Get it's dual plane 2 brl. cast iron intake, Carter carb, different fuel line routing, electronic ignition, and the charging system.
I can promise you will be surprised at the difference in performance. I'm quite satisfied with mine. All done for less that the cost of aluminum 4 brl. intake alone.
Still running the stock air cleaner too.
 
The 2 bbl sucks , even without headers the 4bbl will be an improvement , probably get better gas mileage with the spread bore carb , at least it did on mine . Adding headers made a difference as well , the added noise of headers may have added to the perceived increase in performance
 
Just some food for thought, if you are looking at a 500cfm 4 bbl. how would that compare to say a 500cfm 2 bbl?
 
I wont argue. There is very little difference between the 67 Carter 2 barrel and the 73 Carter 2 brl. other than wear. I found it was the single plane intake and mechanical points ignition that sucked. Granted I don't raise the hood at shows/cruise-ins. There is nothing fancy to see under there. I can fire up and go there in dead of winter. I'll be alone. All the hot rods are hiding indoors. Hot start, cold start, no difference. Always ready to ride. I wont wear out my hood hinges in just checking fluids once in a while. Adding a coolant recovery tank was a important part of that as well. One more point before I unsubscribe here... In 48 years no one has felt that your car needed a bunch of aftermarket brand named bling to get from points A to B. It still doesn't. You can get a more enjoyable journey from a 67 273 using the same parts that Chrysler made for later year models and fuels.
 
Thanks all. I appreciate the input greatly. It's been a long while since I have owned a 67 Cuda......and back then I didn't have the funds to improve the car. This is all new learning experiences and I appreciate the help. I am learning a lot from reading these forums. Thanks again for helping out a newbie.
 
Just be careful adding a hipo top end to an old tired bottom end or things will go south quick! My buddy did cam,heads,intake and few other great add ons but left bottom end stock and it was a 150,000 mile great running small block mopar and then after a few weeks the bottom end let loose and it wasn't pretty. Its simple and cheap to do simple rebuild to be safe and save major headaches later.
 
jerry6 said:
Almost nothing done and talked about here is necessary , why don't you just buy a Lada to get where you are going ? And my car starts in 20 below , I just chose not to drive it on our salt covered roads . This is an entusiasts site , you sure sound like you got buckets of it , 12 posts in 7 years , WOW . One thing in your post I believe 100% , when you state this " I'll be alone " yes I believe you are and will be .
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I think anyone should be able to voice an opinion without being belittled. It is up to the OP to decide what to do with his time and money. The valid point is: Adding a 4 barrel carb is more complicated than one would think. However a "67" 273 is almost 9:1 compression and should have a solid cam, which lends itself to simple mods that should give more performance and mileage. It is also hard to argue with a 48 year old car that always starts and gets to point A and back without a second thought.
 
dragondan64 said:
Just be careful adding a hipo top end to an old tired bottom end or things will go south quick! My buddy did cam,heads,intake and few other great add ons but left bottom end stock and it was a 150,000 mile great running small block mopar and then after a few weeks the bottom end let loose and it wasn't pretty. Its simple and cheap to do simple rebuild to be safe and save major headaches later.
Click to expand...

Granted a rebuild is always great if you can do it, but I don't think I'd be worried about the power. Swapping from 2 to 4 bbl isn't going to add so much power that a stock shortblock will blow up. As far as compression I think you'll be lucky to have 8.5 IF it has the shim head gaskets.
 
CultClassik said:
... As far as compression I think you'll be lucky to have 8.5 IF it has the shim head gaskets.
Click to expand...
Steel shim gaskets were never original and were available for racing. Early 273s were close to 9:1 with stock composition gaskets. 273's were never smog motors.
 
My 67 273 looked like it had shims but it was already apart when I bought the car. I know what compression they are advertised, but according to my measurements, and I think most will agree, advertised is on the high side. I used the 67 273 heads on my dirt cheap like new 318, here's some info:

2658920 (66-67 273 heads), closed chamber, milled .015, ported by me, hardened valve seats, Comp 901 springs, stock retainers/locks/valves, fresh valve job, mr gasket 1121g gaskets

318 heads measured 69cc while the 273 heads measured 62cc after milling (factory listed at 57cc)

Old (felpro) head gaskets are said to be .050 or more compressed New (mr gasket) head gaskets are advertised at .028 compressed Bore is 3.94 (.030 over stock), stock stroke of 3.31, effective dome volume 0 (not taking into account the volume of the valve reliefs, I'm not going to mess with it), deck clearance of .100 (measured).

I don't know how the 273 piston specs compare. It's rated at 8.8, my guess would be more like 8.0 but it's hard to say without knowing exactly what gaskets and the rest of the short block specs.

Just info, not really important for this post.
 
57.3 cc was NHRA minimum for early 273/318 heads. It takes a .040 cut to get to that minimum cc on the largest chamber. .040 / .0053 = 7.5 cc + 57.3 cc = 64.8 cc chambers of uncut heads. 273 pistons are only about .02 below deck. Factory head gaskets were about .029 though we never measured them. That is why 273's ran strong for their size, same ports, same valves, higher compression, good quench, and a solid cam. Probably closer to 8.8 from the factory than 8.0. That is why stock 318 numbers do not translate to stock 273s.
 
Lot of difference in deck clearance!

Oddly enough your avatar reminds me a I just saw a 65 for sale locally, 273 Commando with 4 speed. It's tempting.
 
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