273 or 225?

/6 guy's are like 360/408 guy's they all think you should run what they do. Run what you want as long you know the compromise.
Not all of us. I recommended staying with the slant six, mainly based on the fact that he is still a teenager, with a limited budget, and very limited experience working on cars. He can gain experience, working with the slant, get the car running, and have some fun with it. Then if he wants more, do the V-8 swap in the future.