596 casting or 308 casting for mild 360 4bbl

popinsmoke said
Gentlemen,

I am building a mild 360 4bbl in my 78 Magnum, The short block is the stock low compression 360 2bbl that Ma Mopar made millions of.

Now I am in the process of installing a Comp Cams XE268H complete kit as well as an airgap intake and street demon 625 4bbl carb.

The lean burn system has been ditched in favor of the MP electronic conversion with the orange box.

Plans are at this time to run the big outlet dakota exhaust manifolds in to a 2.5 inch true dual with an X pipe.

So my question is the car has 596 casting heads currently sitting in boxes that came off the car and 103k miles, I have access to a pair of 308 castings at the local bone yard as not allot of Mopar guys frequent my yard.

Everything that I have read says that the 596 castings are the best of the smogger heads but the 308's are the best pre magnum head, my question is how much better?

If I am having 2.02 valves and bowl work performed anyway is there that much of an advantage to the 308 "swirl port" design $ for $?

Also looking for the MP head porting templates anyone know a good source to find them?

Thank you in advance for any advice.

The swirl port design is junk. Again, it is JUNK. It takes a massive amount of work just to correct the chamber. This has been published in the latest Chrysler small block manual that I know of.

Do not get caught up in crap that was designed for CAFE standards and missions bullshit. It does NOT translate into HORSEPOWER.
I will give you one example. In the 1980's you couldn't pick up any tech article and not have it be full of crap about swirl and tumble and how to get it so you can raise your compression to the moon and still run pump gas. How you could improve fuel economy with tumble and save your money back in just a year. It was total BULLSHIT. I do anything I can within reason to kill swirl, because I want the incoming charge to have every single bit of its potential to fill the cylinder, not waste energy trying to force the charge to swirl or tumble.

That is one quick, nontechnical fact about not getting sucked into using emissions crap to make horsepower.