back in the 90s..i was spinning a cast crank to 7500 rpm for two years...with heavy stock rods and heavy trw pistons...changed gearing from 5.38 to 5.13....spun engine to 7000 rpm for another 5 yrs before stock rod broke...crank never got damaged...
with today's lighter rods and pistons.....running a cast crank should not be a problem
