Lead on a 408. Should I do it?

No number matching going on in my build. Pulling a 318 from my 72 swinger for the 68' 340. And the main reason behind not wanting to port the heads is in my mind the x heads are more valuable to someone in stock conditions so should I ever decide to upgrade to aftermarket I could sell the heads easier if they are not ported. Also I feel like if I want performance heads I am better selling my x heads and getting aluminum heads.

Also the motor is out and at the machine shop so no chance of hearing it run. I am going to call him Monday and see what everything is.