318 crankshaft specs

Why go 273,or 340 crank and spend money getting it balanced instead of going with another 318 crank and have a basic plug and play set up? (that is if it comes down to him needing a crank of course)

Plus not to mention he has .060 over after market pistons.....which pretty much eliminates the hole piston weight aspect of everything...pretty much if you have to swap out the crank,you will have to have your rotating assembly balanced going off of what you say correct?