Best aftermarket intakes for an early 273?

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his 273 is stock,, and low compression and a 2 barrell cam,, a single plane intake is for high RPM,, a dual plane is what you want on a street driven car,,even more so with low compression and stock cam,,rear gears,, stock to mild,, dual plane works on the street off idle,,,a single plane comes in around 2500 rpm and up,,,street driving you want a intake and cam that comes it at or just off idle,,,

single plane will make more power on the dyno providing the motor is built properly for high RPM,,

as for the 273 bolts,, they may be smaller in dia,, but the angle is also dfferent from the 64/65 to 66 and newer,,,that why the holes on those intake are hogged out,,

as for the kick down,,if you can cut the 2 barell linkage,,,add a piece and re weld,,or attach it together,,,,you can modify the 2 barrell bell crank,, that would be the cheapest,,,but the cable kit comes with all the brackets,,and is a simple install,,,,LOKAR,,, BUCHLION OR JUNK YARD,,,,
 
Yeah I found the Lokar kit on summit, I'll probably be ordering that when I go to do the conversion.
 
'64 Cuda said:
I ran an Offenhauser 360 Equa-Flow (part #5699) on my early 273 with 10.5 to 1 pistons, .030 milled heads, 4 speed, dual point, street hemi profile cam, 3.91 gears, headers, & various carbs. I used a stock Carter 4 bbl, a Carter from a 383, an 1850 600 cfm Holley & the absolute best performance was from a Holley 3310. The engine was a screamer with each combo but putting the 3310 on it was like adding a steeper set of gears. It was never much for bottom end torque though, no matter what the combo was. But I had a lot of fun with it. :snakeman:
Click to expand...

Yeah, thats the split plenum deal, I don't like them either. Just not good for Chryslers in General, but man, will it make a FE Ford run!

For low RPM, other than the dual port, Offey's weren't good at it. (Love my Port O Sonic)


I just am concerned with all the "you NEED a dual plane manifold to make torque on your 273".........

When comparing a Xcelerator to a LD4B *Low Rise Dual Plane 4 barrel*, yes........ BUT, again, the stock design small runner small port single plane makes more torque, anyone who has ever done this knows. Not saying he "needs" a dual plane, or a single plane, but, when it comes to small port engines, there is exceptions to the rule.

Will the Dual plane make more torque than a MP Single plane on a 273?

YES

Will the Dual Plane make more torque than a Street Dominator/marine single plane?

NO


WOuld it be worth running down a hard to find manifold over using an already found dual plane?

Not a chance.











The whole purpose of my argument is the simple mis-information that ALL engines will make MORE bottom end from a dual plane. It's just simply wrong.

OK, the horse is dead.
 
Actually, I believe "LD4B" stands for Late Dual Plane 4Barrel ('66-up 273-318 ), as the previous version was "D4B"('64-'65 273).

Just semantics...not important.

...and ,actually, the stock, flat, single plane, cast-iron "pig-of-an-intake" makes pretty good power.
 
65Val said:
Actually, I believe "LD4B" stands for Late Dual Plane 4Barrel ('66-up 273-318 ), as the previous version was "D4B"('64-'65 273).

Just semantics...not important.

...and ,actually, the stock, flat, single plane, cast-iron "pig-of-an-intake" makes pretty good power.
Click to expand...

I think you're right about the semantics. As to the cast iron pig, I used one of those before I bought the Offy & the Offy made a night & day difference, great improvement over the factory manifold. If I remember right, a factory 318 2bbl manifold has a higher rise than the 273 4bbl. It worked, but to me it never looked like much thought was put into it.

One more flog at the dead horse. I had a friend with a 318 in a 72 Challenger who ran a Dual-Port with a Thermo-Quad. Performance was okay but nothing spectacular. Admittedly, he wasn't much into trying to get a lot of performance out of his car. He was more of the bolt-it-on-&-not-mess-with-it-any-more kind of guy.

Kind of funny story. About a year out of high school his family moved about 400 miles away to Arkansas. The following Thanksgiving I swapped in a set of 3.23 gears & drove down to visit him in my Barracuda. He had moved before I had done a lot of the work to my engine. I let him drive my car & I can still remember him punching the throttle with a big grin on his face. He kept looking over at me & laughing and saying "I can't believe this is just a 273!"

Like I said, I had a lot of fun with it.
 
65Val said:
Actually, I believe "LD4B" stands for Late Dual Plane 4Barrel ('66-up 273-318 ), as the previous version was "D4B"('64-'65 273).

Just semantics...not important.

...and ,actually, the stock, flat, single plane, cast-iron "pig-of-an-intake" makes pretty good power.
Click to expand...

Could be right.......

My next question is, what does the SP2P mean?????


What engine was the LD4B made for?

Dual ports take a lot of tuning, but are so efficient, and crisp when they are done!
 
D4B is a direct early 273 fit. Anything else bolt holes will have to be elongated. They come up on the Bay from time to time and that's what I would use.JMO
 
dodgetkboy78 said:
Could be right.......

My next question is, what does the SP2P mean?????


What engine was the LD4B made for?

Dual ports take a lot of tuning, but are so efficient, and crisp when they are done!
Click to expand...

SP2P = Single Plane / 2 Plane

LD4B was designed for '66-up small port 273/318 heads.

D4B was for early 273 ('64-'65) heads(with the weird bolt size and angle.)
 
I haven't seen one for over 30 years but didn't the 273 4bbl manifold have 4 holes in the top where the carb sat, opening into an open plenum?
 
Wrong, the D4B is aluminum as is the LD4B, both Edelbrock. The LD4B is for post 65 heads(intake bolt angle and size).
 
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