I agree with what Don said. I have a small port head on my '57 270. According to most it is the worst choice for performance. It has served me well since 1978 in my every day '53 Chevy pickup. I've never hooked to anything it wouldn't pull or loaded it with something it wouldn't haul. It will do 75 all day and get 17+ mpg. What vintage is your 270? Head choice will dictate piston choice. A little work on the small port head will serve you well on the street. If you can get the 302 head for a good price do it. If you don't use it you can sell or trade it.
