Question about the price of 340s
non numbers matching car? save your cabbage bro. punch out a pre 72 LA318 and find a forged crank. just don't overbore past .04 of a 340. you cant see cylinder distortion or compression blow by past the rings cause of out of round cylinders. the smaller main journal non 360 crank will keep bearing speed lower. the shorter stroke crank will make rpm quicker and be more fun to drive on the street. best to keep power below 500 hp to keep from eventually splitting the cylinder walls. IF YOUR AFTER HIGH HORSEPOWER, find an old X block or better yet find an R block and change the lifter angle to 48 degrees.
those 2 type blocks are worth throwing cabbage at to acquire, within reason.