I have a chance to buy a standard 312 block and crank.  I am going to check it out soon and was wondering a fair price to offer.  I think it will be only the block with maybe the rods, and the crank.  According to the seller it has been cleaned and magnafluxed.   I don't have a dial bore gauge, is there a quick way to measure bore, and journals.  I was thinking some calipers to give me a rough estimate.  I know the Id#'s and sizes to look for, anything else I should check out?  Appreciate any help.  Was going to rebuild my 292 but might go with 312 if checks out.