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#1
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I was searching a local bone yard for parts when I came across a set of "302" casting heads. They look ok and the valve stems do not seem loose. As I have been searching for a set of "308" heads for six months with no luck I am tempted to try a set of "302"s. As I live in the Wash. DC metro area the cost of everything is out of sight. Most yards would sell a set of heads for $250+. That's you-pull-it pricing. I have however found a place that has 3 heads for $50 each sitting on a shelf. That price is too tempting.
So, Mopar guru's, what would using these heads do? Will they fit without any mods? I have a '79 360HP stock with the following mods: Street dominator 300-Z intake, points ignition (soon to be MSD), TQ off a '73 440, and cold air cowl induction. The car is my daily driver and rarely sees the track. I am looking for more power but MUST keep it smog legal. I am not looking to spin the engine more than 5000 rpm but can use all the low-mid torque I can get. Any bad points I should know about? (piston goes .0X above the deck and will colide with the head...etc.) Alpha Geek ------------------ Im fluent in several forms of Nerd, including Geek |
#2
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I'm sorry but you said the piston is .0X above . Whats .OX ? And you said you have points in a '79? Now I'm dazed & confused.
Soooo, if you have a positive piston height,the chambers must be open. Otherwise BAM !!!! I'll look into the heads in the morning. I'm unsure of them. I think someone wrote about those early last week. |
#3
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They are closed chamber, made to use with flat top pistons so I wouldn't use them if I were you. On my 1979 318 it raised my compression quite a bit, possibly as much as a point. On your 360 with a slight dome it could go well over 10:1. Also the ports are designed more for a 318, i.e. smaller port window and smaller valves, which might be good for torque but not that great for breathing. You might be able to resell the heads and use that money for a set of 308's, I dunno. Good luck, cruzerjd
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#4
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My reference to .0X pistons was more of a question than a fact. If I have the correct term here what I want to know is does the piston have a negativepositive deck clearance ? In other words when the piston is at TDC some part of it sticks out above the top of the block. I once had a 318 and the top of the pistons would not reach the top of the cylinder at TDC thus had a positive deck clearance. Positive refering to more volume lower CR and negitive less volume higher CR. I apologize if I am using the wrong terms but you get the idea.
The '79 360HP in my 300 has stock pistons. The only things I know are, the Chilton book it lists the CR at 8.0 and it has "dished" pistons. My guess is that they sit down below the deck at TDC, but I wanted an experts opinion. I thought it might be fun to give them a shot. I have read that they can be ported and with the 1.88 I and 1.6 E valves installed they will flow as good as stock 360s. Yes, I swapped the Lean Burn ignition for points. It was $30, ten min, and one wire. I am planning to go with a MSD box later this year. Alpha Geek ------------------ Im fluent in several forms of Nerd, including Geek. [This message has been edited by Alpha Geek (edited October 14, 2000). |
#5
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In that case, the piston sits low in the cyl. so you won't have a problem bolting them on. Although cruzerjd has a point. "Also the ports are designed more for a 318, i.e. smaller port window and smaller valves, which might be good for torque but not that great for breathing. You might be able to resell the heads and use that money for a set of 308's."
Depends on the target power of the eng. |
#6
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If it were me, I would buy the 302's and re sell them just to grab some extra cash. I wouldnt use them on your 360. As you already know the 302's were the high swirl design for 318's and were closed chamber. the 308's are the ones you probably should still go with. I dont remember about which style chamber it is. Call Hughes automotive. He would know if there was a collision course or not. You can also use the search button on the upper area of this site and type in 302 or 308. It will automatically give you a jillion posts on both. I posted some head info before and I got a lot of great replies...good luck...DJ
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#7
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Thank you for the info. It sounds like I should get them and resell or swap them.
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#8
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The 308 from my understanding are open chambered heads. I could be wrong though. If you put the 302 on your dished 360 it will help the compression. Also as stated you can port them and enlarge the valves this will help the flow for the 360.
Also with the small ports and swirl design this will help the low end torque as if a 360 needs it. But since you aren't wanting to spin higher than 5000 I think they would be fine. Maybe even with the larger valves and leave it at that. Christian ------------------ 68 'Cuda 383 Formula S recreation Working on adding EFI 69 'Cuda Race Parts Car 76 Duster 273 recent transplant 95 Neon 2.0 SOHC best of 16.96 84 Dodge Ram D50 transplanting 360 |
#9
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308's are open chamber heads. I never measured the chambers, but htey were said to be slightly smaller than the older 360 chambers. I think if they are, the difference is very small. I replaced a set of mildly pocket ported 2.02/1.60 '915' heads with untouched 308's, and the performance increase was noticable. Couldn't believe it since the ports were smaller and the intake ports were severely restricted by the pushrod hump, but that's how it was. And the chronodeck confirmed that.
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#10
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As I have never been one to let a little criticism of my radical ideas deter me, I have decided to go forth with the plan. In college business classes I learned the some of the best things came from ideas "that would never work".
It seems that I should put in the 1.88I/1.60E valves and do some port work. I found several articles on how to port the 302 heads and on un-shrouding the valves. Does any one know what size to bush the push rod holes so I can grind the bump out of the intake port? What material should I use? (Alum?, brass?, steel?) I will let you know how it goes. Heck, the worst thing that can happen is it runs like crud, lesson learned. Alpha ------------------ Im fluent in several forms of Nerd, including Geek |
#11
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at $50 a head for the 302's you won't be able to resell and make any money in my opinion,they are just to plentiful,I will get as many sets as anyone wants if your willing to pay $50 per head for them.
Now I put a set of 302's on a 360 in a motor home and it gave it a lot of low end power but it fell off big time in the upper RR's but I left them stock,bigger valves and some porting should make a big difference in the way they act. |
#12
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I would get the 308 castings.
------------------ [This message has been edited by BigBlockDuster (edited October 17, 2000).] |
#13
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I think Alpha you will do just fine. With the bigger valves and the bowls opened under them, maybe opening the intake port mouths to 360 size in height and blending the 'matching' long to the port would give you very good results at what you are looking after. Maybe even matching the port in width, but the pushrod hump forces you to make a pretty sharp blend. How ever, widen the port at this point as much as you dare. Mopars are well known of their very very low CR's, so I would use a MP thin gasket to get all the benefit out of the small chamber. Quench would be nice, but the 360 has dished pistons that sit in the hole, so I think it's out of question.
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