heads for a 318

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duster731

duster731

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im trying to find out what kind of heads other than aluminium heads would be good for my set up.............


i have so far a edel performer intake a quadrejet carb a cam kit with 445/468 im building this for street performance and its going into a 73 duster... and everything else is stock

i heard that some 360 heads would be good or swirl port 318 heads so let me no thanks..
 
Dont use the 360 heads.They have large combustion chambers and will drop your compression in the 318 to as low as 7.5:1.Better off to use some ported 302 casting # heads. They have swirl ports and a small heart shaped chamber that will bring comp up to about 8.5:1 without milling.The ports are small but this will work better with the intake and cam you have.Put a 1.88 intake valve in the 302 head and do some bowl work.

Should make about 300 hp.
 
The "302" casting heads are around, too. Any 86-92 dodge or plymouth car with a 318 should have them. I got mine off a 87 diplomat.
 
the new RHS heads will work. They have 62 cc chambers and with the right parts will work nicely I am using a set on my 318
 
360 heads with the 1.88/1.60 valves will work just fine,my buddy is running a set with 60 thousand shaved off to help with the compression,on a '77 smog 318 motor and has gone 13.75 with it..if you can find a set of 302's that aren't cracked your lucky..
 
Not really.I have a set with no cracks.

I agree on the bucks though. The magnum head will require a Magnum intake,but you can get around this by drilling the head for an la intake.Lots of folks feel the 302 casting head is cheaper because of the extra parts required in the magnum swap.I disagree.To get the 302 casting to flow as good as the magnum it will require about $1000 worth of porting.

The only extra parts you need are mag specific head bolts,hollow pushrods and oil through lifters. The lifter will come with any aftermarket cam you buy.Just check the lifter part # and compare it to the amc #.They are the same.

You could get the bolts at the wreckers. Alomst every motor will require a custom length pushrod to get valve rocker contact right so thats another non point.

I've been trying to sell the mags I have to no avail.Due to shipping costs it looks like I will have them until they are used on one of my engines lol.
 
Junkyard magnums, good option. I have not heard of drilling the magnum heads for an LA intake? It seems like the magnum holes would be in the way... Maybe I am just not envisioning this correctly.... got pics?

The 302"Swirl port" heads are not going to flow as well as the magnums, but they would be the best option for the parts you already have, IMO. They are decent in stock form and with some mild mods can be pretty good. I good mod is to change the ex. valves to 1.60s if it is in your budget. Or just have them cleaned up, and maybe pocket ported. I also would run the MP thin head gasket with these to give a little extra bump in comp.

RHS heads if you want to build a beast later on. Cost for the heads is going to be more than either of the two other swaps mentioned in most cases. But a very good option to start a base for a higher powered top end(More potential for the money). I hear their combustion chambers are on the large side for a stock 318 though, so even though they wouldn't be as bad as 360LA heads, probably wouldn't be your best option without a lower end overhaul and zero deck or close.

360/340LA heads: too big on the combustion chamber to make any sense. Don't do it unless you rebuild the bottem end and use pop up pistons.... but then you intake is wrong... so again, no sense.
 
I like Dartboy52's take on the heads. I do think the 360 heads milled down would be a good performing head in the right arena though. Stroked is right about that head being able.

The 302 is capable when massaged. IF a pair can be picked up for a decent cost and also workd on for a decent cost, it could be a head worth investigating w/360 valves and a pocket porting. It should be under a thousand bucks done.

Again, the right head for the right combo to fit the bill your looking to fill.
 
Dartboy52 said:
Junkyard magnums, good option. I have not heard of drilling the magnum heads for an LA intake? It seems like the magnum holes would be in the way... Maybe I am just not envisioning this correctly.... got pics?

The 302"Swirl port" heads are not going to flow as well as the magnums, but they would be the best option for the parts you already have, IMO. They are decent in stock form and with some mild mods can be pretty good. I good mod is to change the ex. valves to 1.60s if it is in your budget. Or just have them cleaned up, and maybe pocket ported. I also would run the MP thin head gasket with these to give a little extra bump in comp.

RHS heads if you want to build a beast later on. Cost for the heads is going to be more than either of the two other swaps mentioned in most cases. But a very good option to start a base for a higher powered top end(More potential for the money). I hear their combustion chambers are on the large side for a stock 318 though, so even though they wouldn't be as bad as 360LA heads, probably wouldn't be your best option without a lower end overhaul and zero deck or close.

360/340LA heads: too big on the combustion chamber to make any sense. Don't do it unless you rebuild the bottem end and use pop up pistons.... but then you intake is wrong... so again, no sense.
Click to expand...

I have a link for a jig you can bolt to the head to do this.It has been done many times.

Used to be a guy at moparts who would loan his jig out.Got mailed many thousands of miles and then it got wore out. I have been thinking about making this jig and loaning it to Fabo members.

http://www.bigblockranger.com/Jig.html

I agree on the 360 heads as well.

I think for the street and a head you dont need to port the magnum would be my choice.

If you can port get 302 heads.

These are budget minded choices.

For deeper pockets..

If you want lots of track time get RHS or eddies.
 
needsaresto said:
I have a link for a jig you can bolt to the head to do this.It has been done many times.

Used to be a guy at moparts who would loan his jig out.Got mailed many thousands of miles and then it got wore out. I have been thinking about making this jig and loaning it to Fabo members.

http://www.bigblockranger.com/Jig.html
Click to expand...


Wow cool deal, I was unaware of that. I would have considered magnums back when if I knew about that... haha. Still looks kinda difficult, especially for those less experienced. If you make a jig that would be awesome, I would probably rent it from you... I wouldn't mine trying out some stock magnums on my motor once I get it rebuilt because I will just be running 302s for now and there are quite a few magnums in the junkyard I could grab for cheap. Eventually I will upgrade to RHS or something with some serious pontential.
 
Dartboy52 said:
Wow cool deal, I was unaware of that. I would have considered magnums back when if I knew about that... haha. Still looks kinda difficult, especially for those less experienced. If you make a jig that would be awesome, I would probably rent it from you... I wouldn't mine trying out some stock magnums on my motor once I get it rebuilt because I will just be running 302s for now and there are quite a few magnums in the junkyard I could grab for cheap. Eventually I will upgrade to RHS or something with some serious pontential.
Click to expand...

I'll keep that in mind.It's not hard to do and I have everything at hand.
 
Here's my 318 with 360 heads, not fine tuned yet. Just put it togther with performer intake and 600 edelbrock carb. [ame="http://www.youtube.com/watch?v=0EBEvNxtUUk"]YouTube- 72 Duster 318 burn out[/ame]
 
Dartboy52 said:
I hear their combustion chambers are on the large side for a stock 318 though, so even though they wouldn't be as bad as 360LA heads, probably wouldn't be your best option without a lower end overhaul and zero deck or close.
Click to expand...

This isn't true: The 62 cc chamber on the RHS heads is smaller than any stock 318/360 head. The 302 heads supposedly have 58cc chambers, but my (limited) experience has been that they are closer to 70cc on average. No 318 is going to make good compression without a lower end refresh or some serious milling, the pistons are too far down in the hole. I can't for the life of me understand why they ever thought they needed valve reliefs in 318 pistons. The lift on the stock cam is less than the pistons are down in the cylinder!

If you are up for tackling the Magnum swap an a new set of heads, I'd give the Iron Ram heads from Hughes a look. They have 58cc chambers. If I would have milled them to 54cc, and run the .028 skinny head gaskets, I could have gotten my stock 318 shortblock all the way up to 9.5:1, but I didn't have any valve reliefs.

Steve
 
Steve, I have a set of 302 heads and there small chambered and closed. The X J etc...340/360 head have the big chambers like 70+. I don't know the cc amount of my 302's, but I can tell you they are small. Perhaps 65 or less cc's.
 
I'd go with a set of EQ Magnums with the LA intake pattern. I've never seen a set of "302s" at 70ccs. Usually closer to 64 after a valve job and no milling. Still much larger than the advertised chambers but smaller by far than 340/360 open chambers.
 
Well, I must have had some freaky heads or did a bad job cc'ing them.

Still...the RHS or EQ/Iron Ram heads will have smaller chambers and much better ports than the 302 heads.
 
LXguy said:
Well, I must have had some freaky heads or did a bad job cc'ing them.

Still...the RHS or EQ/Iron Ram heads will have smaller chambers and much better ports than the 302 heads.
Click to expand...


Are the valves sunk?
 
I have a set of Magnum heads I've been thinking about running, but I'm still not sure about one thing: Valve Springs.

I have a Comp XE268H which is going to be in the .515 lift arena with the Magnum rockers. I doubt the stock springs are up to that.

The Mopar option is machining to accept the non-beehive springs for LA heads with some very spendy retainers from Mopar. I really like the beehive springs and want to keep them.

Is there a low cost alternative for better valve springs for Magnum conversions?
 
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