I recently got a chevy 350 out of a 72 monte carlo supposably it has around 40K miles on it. I pulled it apart mostly and everything seems in pretty good shape, but the cylnders have a very slight ridge in them. when i started to use a ridge reamer it only seemed to remove material from the top of the bore and not from the ridge. I dont get it how am I supposed to remove the ridge without makeing the top of the bore to big?