273/318 heads

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

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.

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 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

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

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

" Wanna guess what the E.T. will be. "

13.68 my guess

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

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.

How to hotrod Strombergs is another thread. The BBD's are neat. I play with them.