340 vs 360

But a 30 over 360 is 367 cubes so for all the additional expense of turning a 360 crank down and doing the balancing you gain 5 cubic inches. Not a a cost effective choice in my book.

Factor in a $400 340 block verse a $150-$200 complete 360, all the additional expense of machining a 360 crank to fit a 340, the mallory metal needed for the internal blance you mention it seems you are very close to the $900 you can can get a 408 stroker kit from folks like Hughes.