318 2bbl to 4bbl advice needed

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scott2683

scott2683

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I'm converting the 318 on my duster to a 4 bbl. I ordered an edelbrock 600CFM electric choke carburetor and I think I'm going to run the edelbrock RPM intake as well....not sure yet. But anyways my question is what else will I need to ensure this set up works right. Will I need a 4bbl throttle bracket, throttle lever adapter, kick down linkage. Thanks in advance for the help!

Scott
 
well....i used all my 2 barrel parts. i only had to bend the throttle bracket out to line it up with the throttle linkage on the carb and extend my kickdown rod about an inch. outside of that mine works great.
 

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Thanks for the knowledge and the pics, sounds like it may be less expensive than I thought!
 
You may be albe to get your linkages to work with the correct chry brackets on the eddy.

Be sure to hook up the electric choke to a good 12 volt source. I recommend the input side of the ballast resistor. DO NOT CONNECT TO THE COIL +. Disconnect both wires from the ballast resistor and check which one is getting power with a test light, and that is the one to hook up into. If you go to Napa and get a flat blade "piggyback" terminal, you can crimp that to your wire from the choke + and then put the other end to the ballast resistor, then stack the original wire on top of the piggyback. You can then take it off later anytime and be able to put it back to stock without messing up any "originality" of the wiring.

However if you are going 4bbl on the intake of the 318, I recommend definately having dual exhaust (2 1/4") minimum. The dual exhaust is needed to wake up a 318. the stock single exhaust is too restrictive. This will also let you take full advantage of the 4 barrels in the carb.
 
i got the intake from a member here..75.00 to my door and new gaskets 20.00
1406 edelbrock carb, almost brand new ..60.00 off CL
fuel line..5.00 , air cleaner 10.00
new thermostat 5.00
carb studs and gasket 10.00
 
73AbodEE said:
i got the intake from a member here..75.00 to my door and new gaskets 20.00
1406 edelbrock carb, almost brand new ..60.00 off CL
fuel line..5.00 , air cleaner 10.00
new thermostat 5.00
carb studs and gasket 10.00
Click to expand...


Total improvement = priceless...
 
73AbodEE said:
absolutely ! between that and the headers, the little 2 barrel engine is much more alive and awake. it really likes the 4 barrel, less than 2 hundred bucks total for the swap.
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Exactly! Once you get rid of the restrictive single exhaust, and then let the intake breathe with a dual plane and 4bbl carb, those 318's really come alive, even with a stock cam.

Then improve the cam if you need more than that...

A good double roller timing chain is another good improvement. Especially when you get rid of those cheap stock nylon timing gears that chip teeth pretty easily.
 
I would go with the performer 318/360 over the rpm. It will give you better bottom end. I have that intake with a thermoquad, a MP .455"-272* cam, stock exhaust manifolds and 2" duals. Stock '81 318 short block in a '70 Dart. Motor runs great. Way more power than stock.
 
Thank you guys for the advice. I can't wait to see what a difference putting on a 4bbl will make. the other intake I was debating on was the performer, so that may be the route I go now. Any cam suggestions with a stock bottom end? I'm also torn on installing headers. In the end I think it may be worth the effort.
 
Summit has their own brand cam and lifters for around $110. There are two grinds available for the small block mopar. The bigger one is pretty close to what I have in my 318. I think the power range listed was 1,800 to 5,500 rpm. For what you are building the smaller ports of the performer intake will work fine. Weiand stealth is a good intake too. I would not bother with headers. They get smashed from hanging too low and leak constantly unless you buy Doug's or tti's and they ain't cheap. Hp for dollar better off with cam, four barrel intake and dual exhaust.
 
Make sure to check to the port sizes on the manifold. I think they are 340/360 size. Using that on 318 heads will result in some turbulance at the intake port of the heads, since the ports on the intake are larger than the heads.
 
If you can weld extending the kick down linkage is a snap. I just slid my throttle cable further forward in the bracket with the eddy linkage adapter and it worked fine. You could also cut and weld your throttle mount if you wished to.

with a 4 barrel, headers, and a cam it will go pretty darn good.
 
Thanks guys, I appreciate the advice, I'm sure I can rig something up rather than having to buy the kickdown linkage and throttle cable brackets!
 
scott2683 said:
Any cam suggestions with a stock bottom end? I'm also torn on installing headers. In the end I think it may be worth the effort.
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For a cam and street use, try a stock 340 cam or a step above it with a set of rhoades lifters. Stay in the 260°/270° range, stay below 280° duration on the cam.

If you choose to run headers, do your homework. I used to run the Hooker super comp headers, but they hang too low. They bottom out on curbs and speed bumps and crush the tubes approx 70%. I went back to stock exhaust manifolds because they would get so restricted from crushing them, stock manifolds then had better flow and didn't get crushed. a good set of headers will have better flow if they don't get crushed with driving.
 
SirDan said:
If you can weld extending the kick down linkage is a snap. I just slid my throttle cable further forward in the bracket with the eddy linkage adapter and it worked fine. You could also cut and weld your throttle mount if you wished to.

with a 4 barrel, headers, and a cam it will go pretty darn good.
Click to expand...

When I did this swap years ago, I just replaced the kick down linkage with one from a 360 4 bbl car. Worked like a dream.
 
here we go with the long tube header BS again. my cheap *** long tube hooker super competition headers dont leak, dont burn wires, easy access to the plugs , they do not scrape, and the paint still looks good after over a year of daily use. if you have your front bumper an inch off the ground of course they are going to scrape.

as sir dan says ...mine dont scrape why do yours ..lol
 
Probably they scrape because the bump stops are gone or you are jumping the car. the hookers I had on my '72 challenger scraped way worse than the black jacks I had on a '67 dart GT.
 
Why not do it right ?
You are a 4bbl throttle bracket,Edel bracket,and 4bbl rod away.
I have the 340 4bbl rod if interested.PM me..
 

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