Originally Posted by 440roadrunner
Actually if that is all you are going to turn it up, the small port heads might even be a slight advantage.
Believe it or not, many years ago 78? 80? I wanted to "get rid" of a 360, and a friend & I had junked a Commando 273, IE 4bbl intake. I put those heads and intake on the 360. That thing was a torque monster in high gear on the highway, but about 3800 you might just as well have shut off the key as try to wind it higher. This was with the factory 360 cam.
This is what i experienced i installed a 268 h in a 77 318 stock no compression changing. Edel performer intake 600 vac holle.
the car was way faster than the original set up.
up too about 4000 then after that i could feel the cam was star-vin for air/fuel !...
My motor head budi back in my high school day-s, use to throw a set of 360 head's on 318's and made them screamer's, man he was crazy 7000 plus rpm's all the time he tried to blow them up! On a simple head cam swap's+4bbl+any size carb! He's why i quit chevy and went too mopar...
Well as soon as i swapped out the heads i lost a slight bit on lower end but the gains to low mid too upper rpm range was huge the motor had so much available to it it worked effortlessly to inhale.. lol.
Then each new combo i increased the V.E. with out swapping the 1.88 s intake / 1.60 exhaust
my new combo is the best yet the little 318 eats up the rpm's so fast! She torque-e and has plenty of upper rpm power and is very street-able, she doesn't even sound like a 318 more like a 340 .
i have been trying to make a video running down the road but the mic.s cant handle all the db's.
With a 650 double pumper i would gain even more down the " unofficial 1/4 " ...