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Discussion Starter #1
hi i wanna build a moderate performance motor. ive build alot of chevy motors but never dodge. i have 67 318 a 85 and 86 318 and a 89 360. i have alitlle money to spend but still on a budget. the motor will probably be put in a 67 coronet. i have a good geared posi rearend and a tranny is not a problem. i want it to have plenty of power to race and economy is not an option. horsepower ovr economy . all help is appreciated. thanks.
 

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Do It In A Van
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You can't beat a 318 for reliability, but for HP I'd go with the 360 buildup although the later engines tend to be thin-walled and can't be bored out too much.

The heads on the 85/86 318 are actually pretty good for stock heads since they have the heart-shaped combustion chambers..aka swirl-port heads, but even those in high HP apps. aren't worth a crap.
 

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318 or 360

You have several options.You could build a quick little 318 if you build it to Rev and put a good gear set behind it.A warm cam in a 360 is a hot cam in a 318.And even a stock set of 2.02 with a 74 340-360 4 bbl intake will make it breathe.Or the auminum copy the LD340 if you can find one.
Or you could turn down the mains on your 360 crank to standard 318 mains. Then bore your 318 to 4".The longer stroke will help in a heavyer car
 

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if you can afford it I would do a 408 stroker on a 360. 318s can rev but the 360 will have to low end torque to get you out of the hole.
 

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318 or 360

Ya those 408 setups are nice,but I wouldn't try it with you 89 360.You will need a pre-75 block.The rod ratio is to high for the thin wall grocery getter blocks.Your 67 318 should be able to go up to a 360 bore or if you sonic test to a 340.I am not saying you should bore out the 318,just explaning how strong a block it is.I bored a seasoned healthy thin wall .030 over and tork plate honed it.It was the best sealing motor I ever built. After ten passes down the track I had cracked one cylinder from the deck down to the bottom of the water jack.My favorite block has been the 360.I drive a 70 duster with a basic original 74 360 that has run 13.3 .The project on the stand now is a 372 cubic 360. Having fun doing it is the key to a good motor.
 

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Discussion Starter #6
ok will this work. what do you guys think
67 318 bored to 4.00"
360 crank mains turned to fit 318 block
86 318 heart chamber heads
edelbrock single plain aluminum intake
holley 750 cfm carb

let me know what you guys think of this setup and any suggestions you might have. thanks for the help
 

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318 or 360

That's an interesting combo. Just remember take nothing for granted,measure everything.And one of the cheapest things you can do that will effect power all around in a dodge is to torkplate hone the block.It makes power in a chev, and they have an octagon cylinder.A dodge has only 4 head bolts,which makes the cylinders square when you tork down the heads.
 

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Discussion Starter #8
so if i use a 360 crankshaft besides turning the main journals is there anythign else i need to do to it? can i use 360 pistons and rods. is there any block to crank clearance issues like there is when building a chevy 383 stroker? is there any other modifications necesary besides boring the block to 4.00" and turning the crank? if you have any suggestions and advice to avoiding problems let me know. im trying to get this motor done by Mid-Americruise which is coming up quickly.
 

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I'm confused. Why would you want to bore a 318 block .090 then spend the money to turn the crank a lot when you already have the 89 360 block to use? How bad a shape is the 360 in? While the 89 360 block may be of the "thin wall" design, its more than up to the task of a moderate performance low buck build up.
 

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Discussion Starter #10
injmopar suggested it and also stroker motors are way better for horsepower. and the 89 360 heads are crap. i wanna use my 86 318 heart heads. and i dont know how good taht block really is its gotten very hot several times and the guy b4 me had it hot several times before from tearing open radiators will 4wheeling with the truck that it was in. my 360 block needs to be bored anyways it has a nasty ridge.
 

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Putting a 360 crank pistons and rods in a 318 isn't building a stroker motor, its putting a 360 in a 318 block which is a lot of unnecessary machine work. It won't give you any more horsepower than a 360 will but will give you less reliability. 360 blocks are cheap, even the early ones, maybe you can find one and start with that. The 89 360 heads arent crap unless they are cracked. Keep things simple and you'll be much happier with the results and save money too.
 

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318 or 360

I was only suggesting what you could do with the parts you have.If you have a 75 or older 360 I would use that.As moparracer said all that work and its just a 360.But you will have to spend the money on a block or to bore the old block more than what you will bore the new one.It is best to keep it simple,but.
To own a dogde, cheap.
To own a 360 not a 340 ,cheap.
The look on their face when they see they had their butt kicked by a lowly 360
priceless.
Now the look on their face if they see the 318 stamped on the front of your block.But thats just me,if I wanted it simple I would built a 350 and just buy everything over the counter.
 

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Discussion Starter #13
ok well i was a litltle confused. i got a 78 360 a 67 318 with X heads. a 89 360 and an 85 318 all complete motors for parts. what would be my best bet or combination for horsepower. it will get a health cam and intake. im thinking the 78 360 but ppl say that the heads off a 89 360 are better than x heads. i dont know a whole lot about dodge motors. what would happen if i stick 318 heads on a 360 i know 360 heads on a 318 lower comp ratio unless u mill them down would it raise my comp ratio? please help
 

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I need some info from you so I can help you out with these heads. I need some casting numbers.

Give me the casting numbers from your 67 318 heads (may be 2658920 or if you have the X heads the number will be 3418915)

The '920' heads have 1.78" Intake valves and 1.50" exhaust valves (they suck)
The '915' heads have 1.88" Intake valves and 1.60" exhaust valves (lots better)
 

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I see the thin wall vs. thick wall debate is opened again here. There is not much truth to this deal. No matter what if you are planning on going more than .040 with the bore you need to have the block checked for wall thickness. You may find a core that has "thick" walls that you can't take to .060 due to a coreshift issue. The "thin" wall blocks tend to have less coreshift issues than the older blocks do. That and to think that the older block has been ran threw it's heat cycle way more times which eventually leads to a brittle block.

As for your parts supply, I would have the 318 block checked to see if you can go to the 4.000" bore with it and if you can get the MP 4.000" storker crank with the small journals. Use the "heart" shaped 360 heads as they have larger intake runners and flow more air. Put 2.02 intakes in it and have them plunge cut to open them up some. Then I'd scounge around and find a good used Edlebrock "air gap" intake for it and run a 850CFM carb on it.

Bennifits to this combo are that boreing a motor is boreing a motor. It costs by the hole not by the size. If you run a new crank you don't have to machine an old one and you still have a heat treated surface for your bearings, not to mention that smaller bearings = less friction = quicker revs & more power.
 
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