273 or NOT 273?

So I'm a huge small block mopar fan , but overall like small blocks in any hot rods. High revving fun. Anyway currently have a pretty well built 340 in my dart and am looking to build another stock stroke 340 for future use , hopefully not needed anytime soon. So , Because the car is a 67 , I always had the thought of building a 12/1 high revving buzz saw 273 to mate with my 4 speed. Would want a low 12 second street car with my current setup (4 speed , 4.56s , 3200 lbs) Before I even think about this , I'm sure I will get talked out of it and that's what I'm looking for , well basically....Can it be done? If so , will it cost more than a 340 build? And how available are aftermarket internals? (Pistons) Basically , is it a waste of time?