2bbl to 4bbl what kind of power increase

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lunacy

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I finally found me a good running 71 318 Dart. Factory stock except dual glass packs with 45,000 miles. It has the Rochester 2bbl carb. I have an Edelbrock LD4B manifold and old Holly 650 sitting in the shop.

On a stock motor what performance gains might be seen by changing over to the 4bbl. If it's not much I'm not going to bother with the trouble and just sell the intake, but if it's a noticeable gain the hot rodder in me has to go for it.
 
It will be modest but noticeable. IMO, before you do this intake swap, do yourself a nice favor. (Since you said "The hot rodder in me") Grab yourself a cam and swing it in.

Being that you have a all stock set up save the glass packs, IMO, I think that a Comp cam from would be a great idea. They have a small line (3 cam) of cams that are designed to work with stock exhaust manifolds.
Like this one; http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=635&sb=2
Or larger.
 
No cam in this motor's future. I have a built 360 waiting in the wings, but have to save up a little $$ to get the extra 8-3/4 I have rebuilt and do the brake swap and what not on it. I just haven't had a running hot rod in a VERY long time, so even if it's a little 318 Dart I still want to drive it for a bit before I rip it apart.

An intake and carb change with parts I already have doesn't involve putting any money and hardly any time into it, just wanted to see if I would get any more fun out of it or not.
 
OK, gotcha. The inprovemnt isn't to bad. It helps, but it's not a big gain.
Of course, theres allways that great sound with a 4bbl.......LOL!

I guess, 15 HP?
 
I did a 2 bbl-to-650 (or it might be a 600, can't remember for sure now) Holley last fall on my 318 Scamp. Can't say I noticed any difference other than the fact that it starts with a flick of the key now (the old carb was in desperate need of a rebuild).
 
We had a Dart years ago with a stock 120,000 mile 318 that ran 18.8.
We put a performer intake on it, a 600 holly and a set of cheap headers and it ran a 16.4 the next weekend with limited one wheel traction and 2.42 gears.
Even with crappy performance gearing, it still really woke it up!

You are not adding headers like we did, but you will still feel it! :cheers:
 
rumblefish360 said:
OK, gotcha. The inprovemnt isn't to bad. It helps, but it's not a big gain.
Of course, theres allways that great sound with a 4bbl.......LOL!

I guess, 15 HP?
Click to expand...

I agree, maybe 20-25?

Increase will probably be in higher end of RPM, but at higher RPM the manifolds and stock cam will start to limit the gains.
 
An Edelbrock Performer with a Edelbrock 600 works very well on the 318.
If you are a Holley guy,you should be able to tweak the 650.
I say go for it. Definately will wake it up.

Rochester 2bbl ? Interesting. Thought they all came with Carters.
 
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