LD 340 on a 318?

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cuda340s

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I have a Edelbrock LD340 manifold, will this unit work on my 318?
 
it will fit and work, but not very well, the air coming down the large ports of the intake will hit the small ports of the head causing a sudden turbulent interruption resulting in very bad flow, a small port performer intake would work much better
 
You need to find someone with an Edelbrock LD4B or similar manifold. Sell the LD 340 to someone one with a 340/360... by the way, here is my latest from the machine shop. Should be dyno'ed soon. Mild 416 stroker with LD 340 intake painted to look more "factory". Yes, I plan on trimming the intake gasket to match the intake.

416stroker.jpg

416stroker2.jpg
 
What if I put a set of X heads on the engine?#-o

I've been using an Edelbrock 2176 with a 600CFM carb. on the 318.

Just looking for a little more performance out of my 68 318. I was going to put a 69 340 in until I discovered that both engines make the same amount of torque (340), only the 318's torque comes on around 2400 RPM instead of 3200 RPM of the 340 engine. I figured that I was only gaining horsepower, correct me if I'm wrong, but isn't torque that propels the vehicle?:dontknow:

http://www.allpar.com/mopar/318.html

Any and all feedback/comments are welcomed, just want to get it right. I believe that I will with all your comments/guidance. Thanks all
 
Sweet looking engine Rob, looks stock to me. Thanks for the photos and info. Good luck with your project.
 
if you have a 340 it is the better choice, the 340 heads on the 318 will drop your compression down really low, high 7's low 8s' the bigger ports and valves will cause you to loose intake velocity costing you torque, the larger displacement of the 340 makes up for this, and a 69 340 is just a GREAT engine
 
Anyone looking to sell a Edelbrock LD4B? I'd even consider trading my LD340 for it.

Or, should I just continue to run the Edelbrock 2176 on it?
 
cuda340s said:
Anyone looking to sell a Edelbrock LD4B? I'd even consider trading my LD340 for it.

Or, should I just continue to run the Edelbrock 2176 on it?
Click to expand...

IMO, stick with the 2176. It is a small port intake. Save the LD340 for a future engine or as swap material for something that you really want/need.
 
2 Darts said:
IMO, stick with the 2176. It is a small port intake. Save the LD340 for a future engine or as swap material for something that you really want/need.
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x2
Also, are you running the stock cam? If so, bump it up. The 318 needs more than a stock cam when using a 4bbl.
 
2 Darts said:
IMO, stick with the 2176. It is a small port intake.
Click to expand...

This isn't necessarily true. The 2176 currently shows as a Performer 318/360, and has the larger 360 ports. I believe that there used to be a Performer 318, which had the small ports, but I don't know if it shared the same #.

I have two Edelbrock 2176 manifolds, both have 360 ports, sort of. 318 intake ports are 7/8"x 1 15/16", 360 intake ports are 1"x 2-1/8". Both of the 2176 manifolds I have measure 1"x2" on the ports. On the other hand, the Edelbrock Air Gap I have (7176) has ports at 1"x 2-1/8". And, just for grins, the old Holley 318 Street Dominator I have has ports at 15/16" x 1-15/16".

So, the 2176 does not have 318 ports. They aren't quite 360 ports either though! I'd bet the LD 340 has 1"x 2-1/8" ports to match the larger ports better.

But, either way, you're still going to have a step in the intake even using the 2176. The old Edelbrock Streetmaster 318's have 318 sized ports, and so do the old Holley Street Dominators.

And as far as 318 vs 340, I don't care what the stock numbers say, if you've got a 340 that's what I'd be running!
 
72 blu, the Performer is considered 318 port size since it's ports are smaller then a 360's. Also, not all 318 heads have the same size ports. They do vary year to year, casting to casting, core shift has a play in it as well. All small potato's, I know.
 
rumblefish360 said:
72 blu, the Performer is considered 318 port size since it's ports are smaller then a 360's. Also, not all 318 heads have the same size ports. They do vary year to year, casting to casting, core shift has a play in it as well. All small potato's, I know.
Click to expand...

Good stuff to know though. The two sets of 318 heads I measured were within a 1/16" of each other, and that was '71 vs 80's smog heads. But I wouldn't be surprised at all if they varied more than that.

I think the Performer's are as close to 318 ports as you can get these days, but compared to the "true" 318 ports on the Streetmaster's and Street Dominator's they aren't particularly accurate. You'd have to do a gasket match to eliminate the step.
 
I agree 100% and your right about the variances on the ports. Very little in amount.
 
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