273 hop up help..manifold carb etc!

-
T

Torkmnstr

Well-Known Member
Joined
Feb 24, 2015
Messages
173
Reaction score
48
Location
San Jose, Ca
Hey guys I have just got a 68 dart with a 273 and I have been trying to find manifolds but have come up really empty which is stumping me. I have been trying to do some research and supposedly the 318 manifolds bolt on to the 273 but not earlier 273's?? So my 68 is safe to swap a 318 onto it?? Thanks all.
 
An Edelbrock Performer, Holley Street Dominator, a stock factory iron 4 bbl intake will bolt right down, no problem; a 500 cfm Edelbrock carb would work just fine. With cam change, and headers you could make slight adjustments to this.

Good luck!
 
So J when I look in summit nothing comes up for the 273? Would I look for a performer rpm for a 318?
 
Torkmnstr said:
So J when I look in summit nothing comes up for the 273? Would I look for a performer rpm for a 318?
Click to expand...

Exactly. Any SB manifold will bolt up to a '66 and later 273, but the 273s all came with small port heads, just like a 318. So for a '66 and later 273, just order or shop for a 318 manifold. The non-EGR Performer is probably your best choice, and I found it worked great with headers and a Holley 650 4150.

Dave
 
The old LD4b Edelbrock intake has been rated as the best for a 273. They have been out of production for years but show up here and E bay from time to time. Many of the intakes have been on many different 273's and then the owner desides to upgrade to a 318,240,360 or stroker. Nothing wrong with a 273. I love the spirit it has for being such a small cube engine. tmm
 
toolmanmike said:
The old LD4b Edelbrock intake has been rated as the best for a 273. They have been out of production for years but show up here and E bay from time to time. Many of the intakes have been on many different 273's and then the owner desides to upgrade to a 318,240,360 roe stroker. Nothing wrong with a 273. I love the spirit it has for being such a small cube engine. tmm
Click to expand...


As normal with the 273, TMM knows best! The D4B (or LD4b with small ports) is an awesome intake for the 273, small ports, but built like the "performer RPM" of today, better to RPM match a hot 273… they are harder to find, but they do show up here and on Ebay. I like a holley carb, but anything in the 500-625CFM range will do you good.

JOE
 
joeboy said:
As normal with the 273, TMM knows best! The D4B (or LD4b with small ports) is an awesome intake for the 273, small ports, but built like the "performer RPM" of today, better to RPM match a hot 273… they are harder to find, but they do show up here and on Ebay. I like a holley carb, but anything in the 500-625CFM range will do you good.

JOE
Click to expand...
You bet Joe. The D4B is a 64-65 273 intake where as the LD4B fits the 66 and newer 273 but the 64/65 LA 273 used 5/16-18 bolts (intake to head)... 66 and newer LA engines went to 3/8-16 Bolts. The early intakes/heads also used a different angle for the intake bolts. The 64-65 and 66 and newer intakes aren't interchangable unless modified. tmm
 
~ 1968 Mopar 273

Best Bets > Aluminum Dual-Plane High-Rise Intakes

* Edelbrock LD-4B ................... 1.05" x 1.95 Port Size ..... 4.90" Height
* Square-Bore Carburetor Mounting-Base

* Edelbrock Performer #2176 .... 0.97" x 1.95" Port Size .... 4.63" Height
* Spread-Bore Carburetor Mounting-Base
-------------------------------------------------------------------------------

Best Bets > Edelbrock Performer Series Carburetors

* #1403 {Electric-Choke}
* 500 CFM > Calibrated for Performance

*# 1404 {Manual Choke}
* 500 CFM > Calibrated for Performance
 
Just put a LD4B on girlfriends 66 barracuda 273 and blowing one tire fire as long as i hold my foot down!
 
Keep the duration @ 50 under 220 & get as much lift as you can. for a good street motor that won't need a crazy loose torque converter to work rite!
 
IMO, the Edelbrock AVS will work better than an AFB.
Tuneable secondary air door! Grab one in a 500 cfm rating.
 
toolmanmike said:
The old LD4b Edelbrock intake has been rated as the best for a 273. They have been out of production for years but show up here and E bay from time to time. Many of the intakes have been on many different 273's and then the owner desides to upgrade to a 318,240,360 or stroker. Nothing wrong with a 273. I love the spirit it has for being such a small cube engine. tmm
Click to expand...

All my research came up with the LD4B as the best choice for my build. They are out there and you can find them. 500 CFM carb of choice and be careful not to go to big on the cam, performance goes backwards after a point. Lots of info on here about that. Good Luck :coffee2: DR
 
cuda64 said:
Know of an intake for that early 273 ?
Click to expand...


If you are referring to the 64-65 273 with the unique head/intake bolts, then you would want to find an Edelbrock D4B. That is the equivalent to the LD4B, but for the unique bolts for the early 273....
 
Yes,smallblock headders are smallblock headders 273 to 360 headders will bolt up. The only ones you gotta watch out for are the later 318-360 heads with the air injection ports. That's an easy fix just tap & plug them with small alen head plugs or tack weld them shut grind down & good to go! Where it gets tricky is what vehicle the haeders are going in. That's where its different early A's (63-66) is real tight & good headders that fit will cost you! Now 67-76 there is lots of choices. id use the smallest primary tube headders for a 273 otherwise it will not help low end torque @ all! Ask how I know LOL!
 
If you are going with cam swap the rule of thumb is a cam is gonna act 10-15 degrees larger in a 273 than 340/360 so a comp xe268H consider good performance street cam for a 340/360. So a xe256H would be it's equivalent for a 273. Don't forget about rear gears 273 needs all the help it can get in the bottom end department.
 
in a pinch, any LA manifold will bolt up IF you hog the holes out to the earlier LA angle and use washers, did that for years on my 65 with a Performer. 25 lbs lighter to boot.
 
You must log in or register to reply here.
-

Back
Top