Ive ran into a problem, maybe some of you can shed some light on for me. I'm attempting to put a head that I believe to be a 283 head on a 310 Block. The block was a power unit and I believe it to be a later engine, tag says Waukesha Dresser on it. Problem is there are two small water holes in the back of the block that this head does not have, but the old head does. The real issue with that is the new head comes about a 1/16" from covering the holes. Is there a difference in the blocks and head from 283 to 310 or is this a difference in age that I'm dealing with. I cant find anything on the internet that gives any details about the block and heads being different so I ordered a VR series engine manual but don't know if it will tell me much, in the mean time I thought I would pick your brains. Any help would be great.