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#512160 - 10/31/09 05:31 AM 273/318 heads
85_Ram_4speed Offline
master

Registered: 06/12/03
Posts: 3306
Loc: Truckville, the capital of NY
I have a couple sets of 273/318 heads sitting around for whatever reason. Besides the "308" heads, are any other heads worth keeping? I can get the casting numbers later, but they are just common heads i believe.
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#512161 - 10/31/09 09:51 AM Re: 273/318 heads [Re: 85_Ram_4speed]
Rug_Trucker Offline
I Live Here

Registered: 01/19/03
Posts: 14489
Loc: Not2farfromNashville, TN
There is a 318 truck motor head with no exhaust crossover, no idea of the casting number. 302's, and the 920 273 heads.
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#512162 - 10/31/09 09:57 AM Re: 273/318 heads [Re: 85_Ram_4speed]
HotRodDave Offline
master

Registered: 01/29/05
Posts: 8166
Loc: Kalispell Mt.
Open chamber 318 heads are not even worth their weight in scrap iron. If they are closed chamber heads like the 920 or 302 they can give average 70s and 80s motors a bump in compression and the 302 head is good for MPG motors because of their high swirl charicturistics, even then they are not worth a lot. The older 315 casting 273 heads are small closed chambers also but need early 273 intakes to match the intake bolt pattern. There is at least 1 other early 273 casting but I can't remember the number. Also the 714 is a really late 318 head just like the 302.
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68 cuda 360 notchback SOLD

1996 Ram 2500 5.9 eddy intake EQ heads, mild cam upgrade great tow rig!


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#512163 - 10/31/09 12:08 PM Re: 273/318 heads [Re: Rug_Trucker]
classof65 Offline
enthusiast

Registered: 07/29/03
Posts: 389
Loc: Tennessee
If you have a good set of 315's, let me know. They are, at least on a 273 in NHRA legal configuration, the equal of, if not superior to any other legal number including the vaunted 302's (which we are currently working with)

All I submit is this - the dyno is the dyno and the ET slip is the ET slip. 315's are a great choice for the 273. The odd angle of the bolts does cause a bit of a problem, but it is only a matter of some end mill modification to fix a later intake to bolt down properly.

Not trying to start a war or be ugly, but we don't get behind the wheel of a flow bench, it is only one tool and doesn't tell the whole story.

Peace, Rev. Mopar (Class of 65, 32 time IHRA and NHRA national record holder)

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#512164 - 10/31/09 02:01 PM Re: 273/318 heads [Re: classof65]
HotRodDave Offline
master

Registered: 01/29/05
Posts: 8166
Loc: Kalispell Mt.
Not going to start a war with me, I do think the closed chamber 273 heads are the best for 273s, no chamber overlap like a 302 head and I thought they flowed more not less than the 302 They made great power in the 273 4bbl motors. I put a set of 315 on a 318 roller motor and it made plenty of tq for the full size conversion van it was in, I had to mod the intake bolt holes and PR holes but it ran better than the 302 headed motor ran.

I do not have a 315 head right now but I do have some 920s that should be legal and use the normal intake bolt angle and when I had them next to a 315 I couldn't find any significant differances, mabey you could fill us in
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I am not causing global warming, I am just trying to hold off a impending Ice Age!




68 cuda 360 notchback SOLD

1996 Ram 2500 5.9 eddy intake EQ heads, mild cam upgrade great tow rig!


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#512165 - 10/31/09 10:13 PM Re: 273/318 heads [Re: classof65]
dart4forte Offline
I Live Here

Registered: 01/31/03
Posts: 10933
Loc: Mesa, Arizona
Quote:

If you have a good set of 315's, let me know. They are, at least on a 273 in NHRA legal configuration, the equal of, if not superior to any other legal number including the vaunted 302's (which we are currently working with)

All I submit is this - the dyno is the dyno and the ET slip is the ET slip. 315's are a great choice for the 273. The odd angle of the bolts does cause a bit of a problem, but it is only a matter of some end mill modification to fix a later intake to bolt down properly.

Not trying to start a war or be ugly, but we don't get behind the wheel of a flow bench, it is only one tool and doesn't tell the whole story.

Peace, Rev. Mopar (Class of 65, 32 time IHRA and NHRA national record holder)




Hey Rev, if you need a set of 315's I have a set. I need a set of 920s for a Bonneville motor.

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#512166 - 11/01/09 04:48 AM Re: 273/318 heads [Re: classof65]
MoparforLife Offline
Too Many Posts

Registered: 01/19/03
Posts: 25169
Loc: Upper Midwest
Quote:

All I submit is this - the dyno is the dyno and the ET slip is the ET slip. 315's are a great choice for the 273. The odd angle of the bolts does cause a bit of a problem, but it is only a matter of some end mill modification to fix a later intake to bolt down properly.

Not trying to start a war or be ugly, but we don't get behind the wheel of a flow bench, it is only one tool and doesn't tell the whole story.


<The truth be told>

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#512167 - 11/01/09 01:39 PM Re: 273/318 heads [Re: classof65]
classof65 Offline
enthusiast

Registered: 07/29/03
Posts: 389
Loc: Tennessee
What all posts on here need is a bit of slap stick humor.... NHRA has "spec" heads submitted to them and they do the measuring and ascribe what is "legal" In their WISDOM, they certified as stock a set of 302's that HAD to be SUPER STOCK (a class that allows porting). Someone did a GREAT job of hiding the work done.

Volume, not flow, is the ONLY possible advantage of a 302 head over the old 315's We're "EXPERIMENTING" with various theories regarding head selection as it relates to our class(es) U/SA and T/SA. The 315's, which we KNOW work are on the shelf and ready to go but the 302's are still being developed. Progress on them is S L O W, which usually means we are at the END of the power production for OUR application. That, by the way, are slower than the 315's PERIOD. One more season trying and it will be back to the 315's.

Our only hope next season to increase performance is that NHRA now allows a FIVE angle valve job which MAY be the great equalizer. We will have to wait and see. AND WAIT FOR NHRA'S NEXT ANTI MOPAR RULING.

Letting a 60 Chevy Kingswood Estate 283 4 Bbl run a TH 350 when they were never an availible option and were only a glimmer in the eye of their daddy is just ONE trial we have to endure. Oh well, the new U record is only 14.19 and we can do that in reverse.

Peace, Rev. Mopar

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#512168 - 11/01/09 01:58 PM Re: 273/318 heads [Re: classof65]
HotRodDave Offline
master

Registered: 01/29/05
Posts: 8166
Loc: Kalispell Mt.
Have you ever used/tested/looked at the 920 head? Are they legal? I assmue you know what they are but for the other guys that don't, they are the 67 only 273-318 head.
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I am not causing global warming, I am just trying to hold off a impending Ice Age!




68 cuda 360 notchback SOLD

1996 Ram 2500 5.9 eddy intake EQ heads, mild cam upgrade great tow rig!


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#512169 - 11/01/09 02:06 PM Re: 273/318 heads [Re: HotRodDave]
RapidRobert Offline
Circle Track

Registered: 11/20/03
Posts: 26257
Loc: Lincoln Nebraska
Reverend, slightly off topic. I have an 80's 318. would one of these earlier closed chamber heads benefit my low rpm mileage effort. I would not want to redrill my intake but one of the other ones?


Edited by RapidRobert (11/01/09 02:07 PM)
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#512170 - 11/01/09 09:27 PM Re: 273/318 heads [Re: RapidRobert]
HotRodDave Offline
master

Registered: 01/29/05
Posts: 8166
Loc: Kalispell Mt.
I am not the reverend but I would think the 302 would give the best MPG because it swirls the fuel more, on the other hand the 920 has a smaller chamber and more quench area
_________________________
I am not causing global warming, I am just trying to hold off a impending Ice Age!




68 cuda 360 notchback SOLD

1996 Ram 2500 5.9 eddy intake EQ heads, mild cam upgrade great tow rig!


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#512171 - 11/01/09 09:39 PM Re: 273/318 heads [Re: HotRodDave]
dart4forte Offline
I Live Here

Registered: 01/31/03
Posts: 10933
Loc: Mesa, Arizona
We took the 920s on my 273 and worked them over. Did pretty much the same with a 302. The 302 flow and velocity went down so we did something it didn't like. I stopped on my 920s when I got 169 cfm average, with 116% port velocity just by smoothing things out especially around the base of the guides and a decent valve job. I also installed stainless valves 1.84/1.58

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#512172 - 11/01/09 11:41 PM Re: 273/318 heads [Re: RapidRobert]
dodgeboy11 Offline
super stock

Registered: 01/31/07
Posts: 1008
Loc: Lund, NV
Quote:

Reverend, slightly off topic. I have an 80's 318. would one of these earlier closed chamber heads benefit my low rpm mileage effort. I would not want to redrill my intake but one of the other ones?




I'd use magnum heads for a mileage setup. Interesting thing with my 360, I have inverse domed KB hyper pistons sticking .004-.005" out of the deck with mopar magnum R/T heads. On the dyno I started with 36 degrees timing and it made 382 hp. Taking the timing down to 32 and it was up to 388. Tight quench with the magnum chamber is apparently very efficient. Car was getting 14 mpg with 3.91 gears and not what I'd call a light foot. 3100 lb challenger. 294 hp to the wheels. 904 transmission. Only difference from the chassis dyno to the engine was crap kinked 2.5 inch exhaust and E body chassis headers to circlie jerk headers through the dyno's 4" pipes.
Anyway, know it's off topic, but it might help some people...
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#512173 - 11/02/09 04:36 PM Re: 273/318 heads [Re: dodgeboy11]
classof65 Offline
enthusiast

Registered: 07/29/03
Posts: 389
Loc: Tennessee
Yes, I think the 273 heads, the 315's in particular because I know more about them, would benefit your effort.

Now I will instigate as I'm sure my humble opinion will be TROUNCED upon immediately.

Magnum heads are all well and good but have things that may make their use less than advantageous. First - find a set that isn't cracked.... That may take a good long time, not to mention money. Then you have to swap cams. Then you have to - oh well, you know the litany. One of the reasons Magnums perform as they do is the 1.6 rocker ratio. Do the ratio thing to older heads and alot of the benefits of the Magnum disappear. Oh yeah - the intake manifold thingie....

Don't get me wrong, I don't dislike the Magnum - they represent a great era, but they are one choice among many and if you are on a budget - I would stick with EASY and readily availible.

I've not done anything with the 920 heads, but have with the 315's and 302's. By the way, the heart shaped combustion chamber in the 315's is as, if not more, effective in producing swirl. The maintain good velocity throughout the RPM band, accept porting without areas of stall, unless you go nuts. All in all a good head.

Seems like EVERY post assumes that the poster wants to spend a ton of money. OR that Magnum stuff is the answer to every topic small block. Let's help one another through our projects by maximizing what we HAVE (money is too hard to come by).

I am just completing an experiment. I have built a .030 318 with 315 heads (kinda cheated up but nothing that would raise the eyebrow of an NHRA tech) a 65 formula S intake, a 670 Avenger carb, one of our trusty record cams (.411 and .399), solid lifters, banana shafts, yada yada yada. I've corrected the ratio like we do on the wagon. It will have a 4600 stall converter, a good 904, and a 4.56 sure grip. All this in a cute little 75 Dart (oh yeah, it's lightened but still looks like new). Wanna guess what the E.T. will be. Probably shock alot of you. Point is, I had this stuff laying around. Don't think for a minute I wouldn't have used "better" stuff if I'd had it but bucks are slim. Suffice it to say this little car will probably run quicker than most think it should and it was a blast to build. How about 2600 in the entire project which includes a to the metal and back up paint job.

Enough of this. You guys are very sharp and I love reading about your antics.

Peace, Rev. Mopar

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#512174 - 11/03/09 01:10 AM Re: 273/318 heads [Re: classof65]
pacifica Offline
mopar

Registered: 12/28/06
Posts: 591
Loc: N.E.Ohio
" Wanna guess what the E.T. will be. "

13.68 my guess

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#512175 - 11/04/09 03:56 PM Re: 273/318 heads [Re: pacifica]
classof65 Offline
enthusiast

Registered: 07/29/03
Posts: 389
Loc: Tennessee
Pacifica

That is probably a pretty good guess. I am expecting the ET's to be in the 13.40 to 13.70 range but am willing to be surprised if they are quicker. If they are slower, well, if it is consistent, we will just run it as is and concentrate on the Class of 65, which, by the way, runs in the 13.6's (273 2bbl) in U/SA trim. Of course it has the advantage of being a pretty "cutting edge" type build.

Peace, Rev. Mopar

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#512176 - 11/04/09 04:51 PM Re: 273/318 heads [Re: classof65]
Rug_Trucker Offline
I Live Here

Registered: 01/19/03
Posts: 14489
Loc: Not2farfromNashville, TN
Quote:

(273 2bbl) in U/SA trim. Of course it has the advantage of being a pretty "cutting edge" type build.

Peace, Rev. Mopar




Still running the Stromberg?
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"The only thing to do for triumph of evil is for good men to do nothing" "NUNQUAM NON PARATUS!"

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#512177 - 11/06/09 04:10 PM Re: 273/318 heads [Re: classof65]
classof65 Offline
enthusiast

Registered: 07/29/03
Posts: 389
Loc: Tennessee
Yes sir.. Still running the faithful Stronberg. I'd love to slip a four barrel on it just for kicks - or even a 500 Holley.... Keep the hood shut and let em wonder.

Peace, Rev.

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#512178 - 11/06/09 05:42 PM Re: 273/318 heads [Re: classof65]
Rug_Trucker Offline
I Live Here

Registered: 01/19/03
Posts: 14489
Loc: Not2farfromNashville, TN
How to hotrod Strombergs is another thread. The BBD's are neat. I play with them.
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"The only thing to do for triumph of evil is for good men to do nothing" "NUNQUAM NON PARATUS!"

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