Re: need info on a 302/308 head
[Re: imfixinmopars426]
#1191337
03/05/12 12:24 AM
03/05/12 12:24 AM
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Joined: May 2003
Posts: 15,487
Florida
scratchnfotraction
I Live Here
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I Live Here
Joined: May 2003
Posts: 15,487
Florida
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#302 head is a small valve/port head with a closed chamber 1.78/1.50
#308 is a 360 big port/valve head with open chamber,the exhast port on a #308 is better and the best head to use,1.88/1.60..they are known for cracking and they are hard to find also.
#302 heads would kill a 408 IMHO,unless they were max ported with bigger valves and would still hold it back.
#302 heads with 1.88/1.60 valves and a max port job will be good for around a 450 HP engine.
the bigger valves will increase flow and keep the port volocity up along with a comp ratio bump with the closed chambers.
I could be mistaken on the CC measurement but it is close IIRC
IMHO a 360 head/X heads with 1.88/1.60 or 2.02/1.60 valve size would be the better heads
Last edited by scratchnfotraction; 03/05/12 12:34 AM.
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Re: need info on a 302/308 head
[Re: imfixinmopars426]
#1191338
03/05/12 12:38 AM
03/05/12 12:38 AM
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Joined: Jun 2004
Posts: 893
Tustin, CA
pishta
super stock
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super stock
Joined: Jun 2004
Posts: 893
Tustin, CA
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302 is a great head for a SB, its closed chambered head around 62CC's but has a intake shape that has a hard turn in it for the larger pushrod holes. I believe a stockish 318 head is about 65CC. 308 head is the 360 head, open chambered. I would use the 308 opened to 2.02 for the stroker though. Great exhaust post.
12 Grand Caravan
06 T&C
02 T&C
96 Breeze
65 Barracuda "S"
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Re: need info on a 302/308 head
[Re: imfixinmopars426]
#1191339
03/05/12 12:53 AM
03/05/12 12:53 AM
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Joined: Mar 2003
Posts: 599
Spartanburg SC
MoparDan
mopar
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mopar
Joined: Mar 2003
Posts: 599
Spartanburg SC
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several yrs ago, I was on a hunt for a set of 308 heads for my 416, the two set I found (salvage yard off the motor) were both cracked....then I took a set off a wrecked 92 truck (two three hours) took to machine shop only to find they were cracked Finally I then took an old set of J heads I had laying around the shop put in ss 2.02 1.60 purchased a MP porting template kit and I'm prally pleased with the performance If you really want new....I would recommend the Hughes LA-X iron heads: 'heart' shaped chamber, larger port size, 1.92 - 1.60 and for about $1100 you will have a great set of heads... 
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Re: need info on a 302/308 head
[Re: imfixinmopars426]
#1191340
03/05/12 01:02 AM
03/05/12 01:02 AM
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Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
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If you don't already have a head then you should look at magnums, they make more HP, TQ and MPG than ANY of the older ones either stock VS stock or ported VS ported. They have a better chamber, better ports, lighter valves, higher rocker ratio, better valve cover sealing... they do almost all have cracks but they don't ever seem to have any issues from the cracks.
If you are bound and determined to use the older heads you have to make compromises, X heads flow best by a tiny bit but no hard seats, 302 is closed chamber but flow sucks, 308 has good quality flow but very sucky chambers, really though all the big port 360, 340, 318 4bbl heads have horrible chambers. If I could pick any LA head for a street stroker it would probably be (reluctantly)a 308.
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: need info on a 302/308 head
[Re: dogdays]
#1191342
03/05/12 08:52 PM
03/05/12 08:52 PM
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Joined: Sep 2007
Posts: 14,889
up yours
Supercuda
About to go away
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About to go away
Joined: Sep 2007
Posts: 14,889
up yours
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I ran a set of stock 87 302 castings on a mild 79 360. Simply because I had them and the stock 79 heads tore out an exhaust stud that had already been repaired.
In an 87 Diplomat I lost about 15-20 mph top end (115 vs estimated 130'ish on the cop speedo)compared to the stock 79 heads and a set of J heads I tossed on it later. However, I gained lot's of low end torque and with an Edelbrock 1406 carb I would get low - mid 20's for mpg.
I would not use them for anything hotter than a mild 360 myself and only if I had a set lying about. If I had to buy a set of heads I would start with Magnums at the least.
They say there are no such thing as a stupid question.
They say there is always the exception that proves the rule.
Don't be the exception.
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Re: need info on a 302/308 head
[Re: MoparDan]
#1191344
03/05/12 11:08 PM
03/05/12 11:08 PM
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Joined: Jun 2005
Posts: 4,041
michigan woods
imfixinmopars426
OP
master
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OP
master
Joined: Jun 2005
Posts: 4,041
michigan woods
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Quote:
several yrs ago, I was on a hunt for a set of 308 heads for my 416, the two set I found (salvage yard off the motor) were both cracked....then I took a set off a wrecked 92 truck (two three hours) took to machine shop only to find they were cracked
Finally I then took an old set of J heads I had laying around the shop put in ss 2.02 1.60 purchased a MP porting template kit and I'm prally pleased with the performance
If you really want new....I would recommend the Hughes LA-X iron heads: 'heart' shaped chamber, larger port size, 1.92 - 1.60 and for about $1100 you will have a great set of heads...
i thought the 302+308 had the same ports,and size,so i bought a fresh set from my engine builder for 300.00,thinking they might be a good torque head for the 408,but now im thinking i might use something else,and use the 302's on a low comp 360....thanks guys,i might call hughes
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Re: need info on a 302/308 head
[Re: RUNCHARGER]
#1191345
03/05/12 11:11 PM
03/05/12 11:11 PM
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Joined: Jul 2003
Posts: 6,167
Maryland
GO_Fish
master
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master
Joined: Jul 2003
Posts: 6,167
Maryland
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I suppose to get 11.5, the DC pistons are domed above deck? What's your plan to work that with closed chamber heads?
Scott B.
"I'm a self-made man... I started with nothing, and I still have most of it!"
68 360 rusty B'cuda 'vert (GO Fish)13.59@ 98.72 mph
69 340 GTS stock 14.18@ 95.60 mph
01 5.9L Ram 1500 Quad Cab 4x4
01 3.5L 300M 16.23@ 86.97 mph
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Re: need info on a 302/308 head
[Re: RUNCHARGER]
#1191347
03/16/12 08:14 PM
03/16/12 08:14 PM
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Joined: Jun 2004
Posts: 893
Tustin, CA
pishta
super stock
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super stock
Joined: Jun 2004
Posts: 893
Tustin, CA
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Quote:
We're building an interesting 360 for my kid's 360. It is a rock crawler so it needs to run at an angle and have lots of response.
I found some rare DC, forged 11.5-1 pistons on Moparts for it and we are going to try the 302 heads we have on it and run it on propane. I am expecting it to be very responsive on the low end and able to run properly at an extreme angle. We haven't chosen a camshaft yet but I'm sure it will be all done by about 4500 RPM.
Sheldon
Need an SP2P? If your going for grunt, you cant beat that intake...
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Re: need info on a 302/308 head
[Re: scratchnfotraction]
#1191350
03/17/12 04:02 PM
03/17/12 04:02 PM
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Joined: Nov 2011
Posts: 2,154
Its a TRAP!
DARTH V8Я
Oh No!! I just had a moron attack!
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Oh No!! I just had a moron attack!
Joined: Nov 2011
Posts: 2,154
Its a TRAP!
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Quote:
#302 heads with 1.88/1.60 valves and a max port job will be good for around a 450 HP engine.
If I may, our 366 in our 74 RR dynoed a 503hp. With a fully hogged out set of 302's w/ 2.05/1.60 valves. I never expected the heads to last. Its coming up on 10 years now w/o any major problems other then a blown head gasket.
As always, results my vary 
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Re: need info on a 302/308 head
[Re: HotRodDave]
#1191352
03/17/12 07:29 PM
03/17/12 07:29 PM
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Joined: Nov 2011
Posts: 2,154
Its a TRAP!
DARTH V8Я
Oh No!! I just had a moron attack!
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Oh No!! I just had a moron attack!
Joined: Nov 2011
Posts: 2,154
Its a TRAP!
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Thats why I said, 'your results may vary' Dyno sheets? ha! long gone! But I'm sure they fudged the numbers ALOT. Seat of the pants maybe 420ish.. Its always been an upper-mid 11 second car (4-speed/3.91's). life isn't always about flow#'s  I should add, never hit water with the porting, but did break through the pushrod wall. Sleeves w/brazing took care of that. 
Last edited by Ice_Eagle; 03/17/12 08:29 PM.
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Re: need info on a 302/308 head
[Re: DARTH V8Я]
#1191353
03/18/12 01:09 AM
03/18/12 01:09 AM
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Joined: Jan 2003
Posts: 4,323
NY NY
340duster340
master
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master
Joined: Jan 2003
Posts: 4,323
NY NY
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What do you use to plug the smog pump holes on the heads under the exhaust ports.?
1966 Dart GT
...down to only 1 mopar for the first time in 15 years!
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Re: need info on a 302/308 head
[Re: imfixinmopars426]
#1191355
03/18/12 02:04 PM
03/18/12 02:04 PM
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Joined: Jun 2005
Posts: 4,041
michigan woods
imfixinmopars426
OP
master
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OP
master
Joined: Jun 2005
Posts: 4,041
michigan woods
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Quote:
Quote:
several yrs ago, I was on a hunt for a set of 308 heads for my 416, the two set I found (salvage yard off the motor) were both cracked....then I took a set off a wrecked 92 truck (two three hours) took to machine shop only to find they were cracked
Finally I then took an old set of J heads I had laying around the shop put in ss 2.02 1.60 purchased a MP porting template kit and I'm prally pleased with the performance
If you really want new....I would recommend the Hughes LA-X iron heads: 'heart' shaped chamber, larger port size, 1.92 - 1.60 and for about $1100 you will have a great set of heads...
i thought the 302+308 had the same ports,and size,so i bought a fresh set from my engine builder for 300.00,thinking they might be a good torque head for the 408,but now im thinking i might use something else,and use the 302's on a low comp 360....thanks guys,i might call hughes
called brian at IMM engines,bought a set of RHS heads prepped by brian....done! also got stroker kit,cam/lifters,and tons of good advice...call them!...mike
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