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  #1  
Old 08-14-2008, 06:21 PM
moparots moparots is offline
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Default 360 Heads on a 318

Hey all, I am putting together a srteet/strip 71 dart 4 dr. We put a 68, 318 in it ,(it was in my wifes old 68 Charger, and its been sitting in the shop for about 10 years) bored .30, mild cam (described on the old reciept as 3/4 race cam) weiand intake, holley650. This motor has very few miles on it since its rebuild about 15 years ago.

When we started it, the left side pipe had alot of white smoke, we figured it might be the valve seats were leaking a lot. If this is the problem, I can get the heads redone, new seats, 3 angle valve job, mild porting and polishing.

My question is, I have a set of 360 heads that came off a 73 motor (cast # 3671587) should I just have these redone? Will they perform better? Will they work/fit? I assume they have bigger valves? but they are smogger heads?

I appreciate any info, comments, ect.... Thanks Craig

PS I just want to play with this motor for a little while at the track and then build a 440 for it, in a year or so.
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Old 08-14-2008, 10:20 PM
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owatajrkiam owatajrkiam is offline
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Should have no problem at all as these will be 1.88" Intake valves and 1.60" exhausts. The 2.02 Intakes can get close to the block,but you should have no problem here!. You could notch the block a bit for piece of mind,if you wanted to!. I had virtually the same setup in a '70 4 gear Swinger when i cracked my 340 block and put everything together on a 318 shortblock while my new 340 replacement block was on the way!. Man ,...that 318 ran like a scalled cat!. I actually tried kicking the rods out of that block and it never broke!. I would float those valves till the cows came home!.Those stock 318's were as tough as the 340's,just a few less cubes!. I sure miss running that car that hard!

Glen
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Old 08-14-2008, 11:34 PM
it's all dodge it's all dodge is offline
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You will lose compression with 360 heads on a 318. What you really have is REALISTLY about high 8s for compression, 8.7 or so. Maybe 8.9. Not the advertised 9.2 to 1. Now, put the 360 heads on, you are barely 8 to one, maybe a bit more, 8.2. The 318 heads you have are about 68 cc. The 360 heads are 74 to 75 cc. You can mill the heads down to the 68, or less cc's (I'd aim for 66 cc, and since milling .0048 cc equals one cc, take off about .050", about 10 cc's, which will keep you in the low 9s for compression. After you do that milling, remember, for each .010 removed from the piston side of head, remove .0095 from intake face of head, so your intake can line up. I'd keep the little valves, if you plan on moving on to BB
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Old 08-15-2008, 01:47 AM
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dwc43 dwc43 is offline
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The 360 heads will be a great add on to your 318. If you have the 2.02 vales in those heads there is still no problem using them in the 318 and you don't have to notch the block at all. Last 360 heads I had milled , I took off .030 and was at 64cc. Nice compression pump and they flow so much better than the stock 318 even if you put larger valves in the 318 heads. A god dual pattern cam works best with the old heads to get them to breath better on the exhaust side.
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Old 08-15-2008, 10:00 AM
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Use the 360 heads. '73 is a bad year for performance but not really a bad year for heads. Keep the 1.88 valves and just back cut them. The 360 head has alot of port volume and the 318 doesn't need to have the port opened up.
Mill accordingly to keep compresion.

White smoke is coolent, new gasket time.
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Old 08-15-2008, 10:17 AM
turbododge turbododge is offline
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IMHO you will be disappointed. Unless the 318 is setup to run high rpms, the big heads will be of no use at the top and will kill the bottom. Do a search here on the topic, it has been discussed MANY times.
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Old 08-15-2008, 11:57 AM
43 purestock 43 purestock is offline
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The 360 heads are not the best setup for what you are wanting. You are gonna replace it with a 440 later, so just check your 318 heads for cracks, replace the head gaskets, and put it back together.
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Old 08-15-2008, 05:16 PM
moparots moparots is offline
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Hey all, Thanks for all the advice. I think I will just keep the 318 heads and just replace the gasket and hardened valve seat/guides. Save the $ for the big block build and run this lil 318 till it blows. (if it ever does)

I was going to have this local machine shop do the heads, what do yall think of the prices? And no Im not affliated them, LOL.


http://www.hanzenginehouse.com/
We offer complete cylinder head machining including-

Hot tank/Pressure Checking/Magnufluxing for cracks
Installing new valve guides/hardened exhaust valve seats
Regrinding valves and cutting valve seats with our 3/angle Serdi type cutter
Resurfacing heads on a CBN machine
Welding of aluminum heads if needed
Porting/Polishing of some applications
Repairing broken bolts/studs

Labor prices for cylinder head reconditioning start at-
Small Block $210/pr
Big Block $250/pr
V6 12 valve $195/pr
4 cyl 8V OHV $175
4 cyl 16V $225, w/adjusting valves and installing DOHC $295
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Old 08-16-2008, 02:30 AM
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rumblefish360 rumblefish360 is offline
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IF you keep the 318 heads, which I favor myself, your in for a bit of porting to match the stock 360's power outpout abilty and it's not in port volume or peak flow numbers. It would be area under the curve, (CFM flow as the valve lifts on a head vs head comparo.) being broader.

If you were keepin g the 318 and not just playing with it, but rather serious in seeking performance from the 318 on a permenant basis, I'd tell ya do the 318 heads over the 360 heads.

It now becomes a problem of price vs cost vs bang for the buck on a engine your not keeping.
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Old 08-21-2008, 02:52 PM
stroker mike stroker mike is offline
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for what it's worth, I have 340/360 J heads on my 318 and the last psi reading I did showed 130 high 125 low. that is not good cylinder pressure, so I spoke to the guys at hughes and got a cam ground that will boost psi and give good torque while spinning all the way to 6. not the ripper top end of a race cam, I drive this car alot alot so I wanted a street cam. Look at the new HMC1326-AL It will help make up for the big chambers if you don't wanna mill those heads... btw if you do mill them be sure to check pushrod geometry...
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