There is no substitute for cubic inches.
I've been driving a 454 daily for the last few months. I love the quick response and the way it pulls strongly any time I want power.
But it averages less than 10 mpg and I'm paying for my fun.
The choice between a 235 or 350 or something else needs to be about what you want your vehicle to be. A 350 will probably be cheaper to build and will make more power, but if your truck came with a 235 the cost of swapping might equal the savings on motor and rebuild costs.
Think about how you're going to use the truck. If you want to drag race skip the 350 or even the 454 and buy one of those new 572s. If you want a cool driver the 235 might be your best choice.
Another 'cool' choice for a '61 would be something like a Buick nailhead, though it isn't likely to be a cheap option.
Beat it at what? Decide what matters to you and choose your motor accordingly. Unless its going to be your friends truck his opinion doesn't matter.
You have the power to choose.
