I'm No mechanic so I am asking this question for the guy who is rebuilding my 235. Is it nessesary to use shims on the crank for a 1957 235? Or is it better to have a process called line boring done which would eliminate the need for the shims but would cost $150.00. The young lad that is doing the rebuild says that shims are a primative method. I don't really know myself but would really appreciate any advice on either method. Thankyou..