help with 273

I bought a 65 barracuda with a "318" in it. Come to find out through some research and actual measureing that it is a 273. I have read a bit and decided I like the idea of keeping the 273. Problems.... it measures 3.665 which I believe is .040 over. It has spun 2 rod bearings and for some reason blew the valve covers OFF the bolts that hold them down. It is a 2 barrel carb but it has solid liftes. So is it that commando bit?

Is it safe to have the crank ground and reuse? Can I go commando with this motor? (just buy a cam/flat tops/4 barrell intake and carb?)

Would it be better/cheaper/easier to just find a 318 and plop in?

I like the nostalgia of the 273 but to be realistic, I want this car to have some pep without putting 5 grand in the motor.

Any help is appreciated. I plan on going through this whole car and was hoping on some experienced advice from a cool forum :)