.030 is fine if it is a forged crank.it used to be common practice to turn a 2.100 l.j. crank to 2.000 s. j. and run aluminium rods....that is .100 off of a new crank...i had one years ago and turned it 9200 rpm's and 8700 in the lights..i was the second owner of the short block,then i sold it to a friend,who ran 8.50's in an x pro stock monza...it is still sitting around and never blew it up..J.M.O