im still digging for some good heads for my 318 build and don't wanna do the magnum swap for various reasons. im trying to find some 302's or maybe 308's from what I can find they are similar or basically the same. what are the chances of them being on a late 80's truck motor? if not what all can I look for them on '85 and up to ?? 318 motors would they all be fuel injected motors at this point in the 80's? thanks
302 heads
- Thread starter ktcnn94
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No. 302s are closed chamber 318 heads. 308s are open chamber 360 heads. They are not the same at all.
ok, thank you for that info, probably saved me some time. would the late 80's dodge truck possibly have these heads, the reason im asking is I found a truck the guy is parting out but he's unsure of the heads on it so I may end up having to go look for myself but its a little bit of a drive.
Yes they probably do as long as it is a 318.
After 85 318s had the 302 heads. Not sure but I think right up till the magnums. You should be able to see the casting # if you take off a valve cover.
The 302's and 308's are almost as bad as the stock magnum heads for cracking. As far as something you can see, sometimes it is, sometimes it isn't. On a set of used, dirty heads you're only going to see the really bad cracks. I managed to get a set of 308's that were in good shape, but not all of them are.
What are your plans for the 302's?
I ask because the 302's are good for bolting on some compression on an otherwise mostly stock 318, but if you're planning on a higher horsepower build you'd probably be better off getting a new set of heads. The 302's have the same 1.78/1.50 valves as every other 318 head out there, as well as the small 318 ports. They do have a better exhaust port than the earlier 318 heads. So, I think they're a great head if you just want to get a little more out of a stock 318, they bump up the compression almost a full point and flow a smidge better. So, for example, if you're trying to warm up a stock 318 with a 4 barrel and headers but don't want to do a full rebuild, the 302's are a great deal, just bolt them on and go.
But, if you're planning on a full rebuild, and want to throw in larger valves, a bigger cam, etc, I don't think the 302's are the way to go, and I'll explain. I have a set of 308's on the 340 in my Duster. It's a '68 340, so the pistons stick out of the bores .018". Because of that I wanted to stay open chamber, which limited my aftermarket options for heads. So, I bought a set of 308's, had 2.02/1.60 valves put in them, had them cut for dual springs and positive seals, had them trued up, and had them ported. End result was that they flow 264 cfm @ .500", which is pretty decent. But, after all of that and the cost of buying the heads to start off with, I had spent enough money to buy a set of Edelbrock 340 heads. Granted, my heads flow a bit better than out of the box Eddy's, but not a heck of a lot.
With the price of heads like the EQ's or Indy LA-X heads, it doesn't make a ton of sense to be doing much work on a set of 302's. I bought a set of the RHS Indy heads for the 318 in my '71 EL5 Gt. Out of the box with 1.92/1.62 valves they flow 246 cfm @ .500". Compare that to a stock 308, which flows around 200 cfm @ .500". And that's significantly more than the stock 302's will flow with the small valves. At the time, I think I paid about $1,300 for the RHS LA-X heads. If you take a set of 302's and open up the valves, buy all new hardware, have them cut for dual springs, checked for cracks, valve job, guides, seals, etc, plus the price of buying the heads, I think you'll have a very hard time staying under that number.
What are your plans for the 302's?
I ask because the 302's are good for bolting on some compression on an otherwise mostly stock 318, but if you're planning on a higher horsepower build you'd probably be better off getting a new set of heads. The 302's have the same 1.78/1.50 valves as every other 318 head out there, as well as the small 318 ports. They do have a better exhaust port than the earlier 318 heads. So, I think they're a great head if you just want to get a little more out of a stock 318, they bump up the compression almost a full point and flow a smidge better. So, for example, if you're trying to warm up a stock 318 with a 4 barrel and headers but don't want to do a full rebuild, the 302's are a great deal, just bolt them on and go.
But, if you're planning on a full rebuild, and want to throw in larger valves, a bigger cam, etc, I don't think the 302's are the way to go, and I'll explain. I have a set of 308's on the 340 in my Duster. It's a '68 340, so the pistons stick out of the bores .018". Because of that I wanted to stay open chamber, which limited my aftermarket options for heads. So, I bought a set of 308's, had 2.02/1.60 valves put in them, had them cut for dual springs and positive seals, had them trued up, and had them ported. End result was that they flow 264 cfm @ .500", which is pretty decent. But, after all of that and the cost of buying the heads to start off with, I had spent enough money to buy a set of Edelbrock 340 heads. Granted, my heads flow a bit better than out of the box Eddy's, but not a heck of a lot.
With the price of heads like the EQ's or Indy LA-X heads, it doesn't make a ton of sense to be doing much work on a set of 302's. I bought a set of the RHS Indy heads for the 318 in my '71 EL5 Gt. Out of the box with 1.92/1.62 valves they flow 246 cfm @ .500". Compare that to a stock 308, which flows around 200 cfm @ .500". And that's significantly more than the stock 302's will flow with the small valves. At the time, I think I paid about $1,300 for the RHS LA-X heads. If you take a set of 302's and open up the valves, buy all new hardware, have them cut for dual springs, checked for cracks, valve job, guides, seals, etc, plus the price of buying the heads, I think you'll have a very hard time staying under that number.
C130 Chief
Mechanical Genius
302's are great 318 heads, if you install them on a 318. But if you honestly plan on making over 300-325 hp, start with something else.
For dollar per hp I don't think it'd the best up grade. Unless there low mileage and don't need rebuilding and are free or pretty close to it. They will only give you 5-10hp at best unless you mill and port them, I don't think you would get a full point of CR with out milling.
Cam, 4 barrel and headers and gears will give you the best bangs for the dollar. Unless your trying to run a much larger cam than stock cr can support money probably better spent else where.
Cam, 4 barrel and headers and gears will give you the best bangs for the dollar. Unless your trying to run a much larger cam than stock cr can support money probably better spent else where.
Oh for God's sake. Do yall have to split frikkin hairs about everything? The 302 heads are designed for the 318. I bet some of yall have never run the damn things before. I have. On both a 318 and 360. They ran fine. They have plenty enough potential to get 325 or more HP on a 318 with good parts choices.
I don't have any experience with Aerohead, but I have heard and read nothing but bad things about them.
I've got 302 reman heads and my car runs great. A lot of mods at once but much better that my old heads.
1qwikScamp
Well-Known Member
I respectfully disagree the port volume just isn't there on the 302s to support 300 horsepower
1qwikScamp
Well-Known Member
They are a fine and dandy head for a stockish build but I wouldn't expect any real power come on guys let's call it what it is they are smog heads never had any intent on supporting power they were designed for fuel efficiency and lowered emissions
ok, so other than aftermarket heads, or magnum heads, what is the best head to use on a 318 to help raise compression. doesn't have to go up much, just a street motor wanting to support a better camshaft. I was under the impression the 302's were my best option.
Treblig
Well-Known Member
Don't the 308 casting have the same closed chamber as the 302 but the 308 is designed for the 360 engine with bigger ports?? 1988 and up used the 308s. They're supposed to flow just like the 576 heads.
treblig
treblig
I found a set of what is hopefully 302 heads, should find out later today. I called the machine shop to ck prices.
I can get the heads for $50
valve job $150
cut and install bigger valves $125 (if I choose to go to 1.88 and 1.60)
mill the heads $38 each
replace the guides $5 each ($80)
I would get the new springs in my cam kit, so I would need valves if I went that way and new seals.
so that's about $500 counting the heads but not counting the valves is this a good route?
I'll port and clean up the runners and bowls myself.
the way I see it is if this is a good deal I can do the 318 bottom end without having to buy the high priced kb pistons.
I can get the heads for $50
valve job $150
cut and install bigger valves $125 (if I choose to go to 1.88 and 1.60)
mill the heads $38 each
replace the guides $5 each ($80)
I would get the new springs in my cam kit, so I would need valves if I went that way and new seals.
so that's about $500 counting the heads but not counting the valves is this a good route?
I'll port and clean up the runners and bowls myself.
the way I see it is if this is a good deal I can do the 318 bottom end without having to buy the high priced kb pistons.
302's, fine. 308's already have the valve size, port size that you want plus they probably breath better on the exhaust side than the 340 heads. If you can grab a cheap "good" set and have them milled .040, that will probably be your best bet. Even milled .040, they still will not have the compression that the 302's will have, however, flow trumps compression every time. If you were never going to go above a 100 % bone stock long block 318, I'd say the 302's. If your going to be doing the whole cam, carb, header thing, I'd personally do the 308's. Less money than rework'n 302's.
replicaracer43
Grumpy Old Man
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NO, the 308 heads are OPEN chamber
CultClassik
Well-Known Member
Yes, .040 is a good bit to cut so there's a good chance the intake will need milled also. You won't need the bigger valves either.
You should google or look around here to get some head tech info. I think it's pretty commonly accepted that a closed chamber 273/318 head with stock valves and mild porting (there is a sticky here on it that I followed for mine) will support a decent bit of power. I don't think you'll need larger valves on a 318 until you start to really push it over 300 (say you're shooting for 400 HP), which is probably going to take a larger cam than the xe268 we were talking about, which is going to need more stall and gear and compression..at which point you might be better off with the KB pistons and open chamber heads that already have larger valves and flow better. That's also the point where I'd be inclined to build a 360 instead, more power with the same money and less effort, and more street friendly.
Also, if you go with the 920 heads, they're not prone to cracking AFAIK like the 302 plus they're not smog heads. They are closed chamber, very close in volume to the 302, enough to where it shouldn't make a difference in compression I believe.
Specs:
2658920 273/318 1966-67 1.78 1.50
You should google or look around here to get some head tech info. I think it's pretty commonly accepted that a closed chamber 273/318 head with stock valves and mild porting (there is a sticky here on it that I followed for mine) will support a decent bit of power. I don't think you'll need larger valves on a 318 until you start to really push it over 300 (say you're shooting for 400 HP), which is probably going to take a larger cam than the xe268 we were talking about, which is going to need more stall and gear and compression..at which point you might be better off with the KB pistons and open chamber heads that already have larger valves and flow better. That's also the point where I'd be inclined to build a 360 instead, more power with the same money and less effort, and more street friendly.
Also, if you go with the 920 heads, they're not prone to cracking AFAIK like the 302 plus they're not smog heads. They are closed chamber, very close in volume to the 302, enough to where it shouldn't make a difference in compression I believe.
Specs:
2658920 273/318 1966-67 1.78 1.50
http://www.forabodiesonly.com/mopar/showthread.php?t=230784
Without zero deck pistons there will be no quench so the closed chambers won't be doing much. If you find out those heads are no good, why don't you just work over your current heads? Milling will increase compression and porting with bigger valves will increase the flow with similar performance to the 302s.
Without zero deck pistons there will be no quench so the closed chambers won't be doing much. If you find out those heads are no good, why don't you just work over your current heads? Milling will increase compression and porting with bigger valves will increase the flow with similar performance to the 302s.
273, on the magnum heads I was afraid they would end up being cracked and if not would need "work" also. I am also concerned with all the other costs that go along with a magnum swap from what I can find (intake,pushrods,roller cam etc). that's why I posted this thread I was curious about more specifics on the 302's and if they were crack prone, because from what I read up until today a lot of the guys on here and other websites praised the 302 because of the closed chambers etc but now I don't know what to do.im really starting to get confused, im just trying to increase compression so I can run a better cam and have a decent running little street car. it will never be raced or anything, just trying to find the easiest most budget friendly way for this to occur. I now i'll need headers and im going with dougs, I know i'll need a gear im looking for that now, I want to stay with the 318 i just like it and already have it.
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